


Lethe

by skelesins (orphan_account)



Category: Undertale (Video Game)
Genre: Angst with a Happy Ending, Brainwashing, Consensual Mind Control, Dom Papyrus, Fontcest, Incest, M/M, Memory Alteration, Memory Loss, Praise Kink, Sibling Incest, Skeleton Ghost Penis, Soul Sex, Sub Sans, Tags Subject to Change, Temporary Character Death, Timeline Shenanigans, he is so reluctant about it at first but will enjoy himself later, is that really what we're calling it well ok then, kind of???, most of this is relevant later on, what can i tag without it being spoilery
Language: English
Status: Completed
Published: 2015-12-29
Updated: 2017-08-02
Packaged: 2018-05-10 07:19:51
Rating: Explicit
Warnings: Major Character Death
Chapters: 13
Words: 30,450
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5576353
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/skelesins
Summary: <blockquote class="userstuff">
              <p>Someone's using dreams to make Sans forget things. Papyrus intends to find the culprit using whatever means possible.</p><p>But they're things that Sans wanted to forget.</p>
            </blockquote>





	1. heartache

He feels… funny.

Sans is locked up somewhere dark. He can’t move his arms or legs, his magic isn’t working. He’s dizzy and his skull buzzes with static.

He’s safe for the first time in recent memory.

A light blinks at him in the corner of his vision. It’s beautiful. Magic, probably. He’s started to forget things since he started watching it. Every time he fixates, his mind is slowly, softly wiped clean, like a forgotten shelf meeting a dust cloth in the spring. It feels amazing to let go of everything, even if he fears some of it might not come back.

The light pulses. Sans responds with a slow blink. Then another.

It pulses again, slower. He blinks again, slower.

A deep voice permeates the dark. It lulls him down further than he thought possible, though he understands none of the words.

He blinks so slowly that he does not open his eyes.

“Sans?”

The dream again. It keeps coming back, different every time. He wakes up aroused. He lets it bleed over to his life, probably because it’s started to turn him on to realize he’s forgotten something. Never anything important, just that the senses of deja vu he used to get that always came with a violent memory now give him a feeling but nothing to draw from. A blank slate.

The thought gives him chills. Has yet to figure out why. Not sure if he wants to.

“Sans? Are you alright?” Papyrus calls again, outside his door. He’s still tired somehow. Shouldn’t be. He’s felt pretty good for about a week now.

Took too long to answer, because Papyrus opens the door. Sans is dazed, sitting up on his mattress. His chest is tight. “yeah, bro? what’s up?”

Papyrus’ brow ridges knit together. “I just wanted to make certain you were alright. You didn’t respond to me, so I… became worried. I’m sorry to barge in.”

“i’m fine. don’t need to worry about me.”

Papyrus gives Sans his patented skeptical expression. “If I didn’t worry about you, who would? One of us has to, and you have such a hard time caring about yourself or for yourself.”

Sans shrugs.

Silence reigns for what feels like an eternity. Papyrus doesn’t leave.

Then, “You had the dream again, didn’t you?”

“how’d you know?” Sans doesn’t meet his brother’s eyes.

“Your soul,” Papyrus says, and gestures down at Sans’ chest. It’s luminescent, trying to break free of the cage of his ribs through sheer pressure. That explains the constriction. “Do you want me to help again?”

Sans nods weakly, collapsing back onto the bed. He’s glad that the Royal Guard has disbanded, in a manner of speaking. He’s not sure how he’d react to being the direct cause for Papyrus’ sudden chronic tardiness, were that a concern. His brother keeps putting him first. But if the only thing suffering from Papyrus’ absence is a flower patch, Sans can live with that.

He’s on the precipice of considering how touching but strange it is that his brother has started actively prioritizing him over his ambitions when Papyrus reaches into his ribcage and gently runs a thumb over his brother’s soul. Sans lets out a bone-deep exhale and lets the tension and train of thought leave his body. Pap sure does know what he’s doing.

The gloved fingers trail over the tiny inverted heart, normally white but pulsating aqua with magical buildup. The massage his brother gives always seems to soothe the strain. It’s sublime in its intimacy, but doesn’t make things awkward enough to bring him shame. He loves Papyrus so much. More than he knows how to express.

“thank you,” he whimpers, and that’ll have to do.

His brother gives him a smile. “It’s no trouble. I promise. You can always come to me with whatever problems you have.”

It’s hard not to believe him when he has his thumb rubbing slow circles into Sans’ heart like that. The smaller skeleton nods. “of course.” Then closes his eyes and enjoys the sensation.

Papyrus’ other hand joins the first and he begins pushing in with both thumbs, applying slow, steady pressure. Sans groans as he relaxes, going limp under his brother’s touch. He doesn’t know how he’s supposed to move like this. His body is far too heavy. He doesn’t know if his brother really understands how intimate this is. But it can be platonic, he tells himself. It will be platonic. Has to be.

“How are you feeling?” Papyrus asks him, still kneading into the soft magical tissue of his soul. Sans tries to look alert. Feels like he’s sleeping with his eyes open, and Papyrus must be able to note the glaze in them, because he just smiles. “You can keep your eyes closed.”

He’s more than willing to comply, sinking further into the bed.

“You can doze off if you want. Nothing important happening today,” Papyrus says. “Especially since you seem so poorly rested. I’d like for you to be able to get some real, good sleep.”

Sans emits a soft, satisfied hum and nods once, then detaches and lets himself drift out.

He wakes, eventually, without dreams. Papyrus is still at his side, though he’s just holding Sans close now. “Sleep well?” Papyrus asks. Sans nods, a touch of bleariness lingering around his edges. “That’s good.”

Papyrus is excellent at warding off the dreams, though Sans isn’t entirely sure that’s what he wants. But it’s good for now. Better to not let them have more influence over his life than he can handle.

The world sharpens slowly. He yawns. “don’t you have something you should be doing?” Sans asks.

His brother stops, considers. “I don’t think so. Unless you’re hungry or something.”

Sans shakes his head. “nah. just curious. you’re usually busy helping people out, though. didn’t think you had the time to be sitting in bed with me all day.”

“It’s Saturday,” Papyrus says, and Sans’ entire body goes cold.

“bro,” he says, then chuckles, trying to hide his anxious shivering by tucking his hands under his arms. The laugh doesn’t sound like a laugh. It sounds like a halfhearted exhale. “you had me going for a second there, making me think i’d slept through a couple days, but you’re being too obvious. it’s obviously…” He strains to remember what day of the week it is. He knows he was told it was Tuesday a while ago, but he’s not sure if that was one or two days ago. He hazards a guess. “thursday. you need to step it up, bro. trying to out-prank the prankmaster.”

Papyrus stares at Sans for a moment. Then, there’s a flicker of orange in his eye, or at least Sans thinks there is, and the television downstairs turns on.

Mettaton is fighting someone, witty catchphrases timed effectively between blows. The sound effects drift up the staircase, too juvenile to be anything but Saturday morning programming.

MTT Broadcasting wouldn’t compromise their schedule for a joke. Even if it was Papyrus asking. It’d be unlike Mettaton to prioritize one fan so highly, especially over children. So it’s not a practical joke at all. He’s lost at least two entire days.

The thought scares him so much he shakes.

“You were up and about during Wednesday and Friday, but you didn’t look… yourself,” his brother states, holding him close. “I thought you were just tired, but I should have tried to wake you. I’m sorry for allowing that to pass.”

Sans shakes his head. “nah, it’s fine. just got a little rattled, is all. this isn’t the first time this has happened, remember?”

Papyrus doesn’t groan at the pun, and that’s off-putting all on its own. He puts his hand on Sans’ shoulder and gives him a light squeeze. “I’m concerned about you, brother. Very concerned.”

Sans doesn’t know how to react to that. But he does think Papyrus has been acting a little weird himself, so he looks down and says, “me too. except about you.”

“Why?”

“you’re different. a lot more serious than usual. it’s creeping me out a little.”

“Once you’re well, I’m sure my demeanor will return to normal,” Papyrus says, but Sans isn’t so sure. He’s been tired before, been sick before, and Papyrus never acted like this.

Well. He supposes that he’s never lost this much time before, either. Maybe his brother is right. “what do you want me to do?”

“Whatever you need in order to improve your health,” Papyrus says. “I’ll go make lunch.”

The taller skeleton leaves his older brother alone in his room and shuts the door behind him.

 

Sans is running his thumb over his pelvic bone and considering getting off when Papyrus tells him that lunch is finished, and he’s very grateful he didn’t start earlier.

He gets up and makes sure he’s suitably dressed before going down the stairs and finding Papyrus eating spaghetti on a plate of his own and a take-out box on the other end of the table. He hops up into the seat and opens it.

It’s Grillby’s. A burger and fries, covered in unopened ketchup packets.

Sans looks up. There’s a level of fear in his brother’s eyes he hoped he’d never have to see.

“is there something you’re not telling me about?” Had he lost more time somehow?

“I’m just worried about you. And I thought it might be helpful for you to have… your favorite for lunch.” Maybe it’s not fear, but there’s a level of discomfort there, at the very least.

“but you hate going to grillby’s.”

“I called him and asked him to box up some take-out.”

“did you put it on my tab?”

“In a manner of speaking,” his brother replies, and looks away.

“papyrus.”

“I paid for the food and for your tab,” he says, then shoves several forkfuls of spaghetti and two whole meatballs into his mouth all at once and stares down at the plate, orange blossoming across his cheekbones.

“you didn’t have to do that,” Sans says, but it comes out weak with gratitude. Truth be told, much of the money he earned working between the hot dog stand and sentry duty went toward making sure their house was still theirs. Grillby understood, but it still nagged at him sometimes that he took up so much food and time and space and didn’t provide in return.

But Papyrus had covered things with what he’d acquired being Captain of the “Royal Guard.” He hadn’t thought it had paid that well to just water flowers and occasionally go around helping people with small tasks, even if it did make a significant difference in keeping the Underground happy and hopeful. Regardless, he wanted Papyrus to be able to spend the money he’d made on something he enjoyed, not on him.

“Brother,” Papyrus says once he’s finally managed to chew and swallow everything in his mouth, “I know things have been very tough for you lately. It’s the least I could do.”

Sans is torn between love for his brother and shame that he couldn’t do it himself, and it comes out in the swelling of bright blue in the corners of his eyes. “i just… don’t want you to have to spend that on me.”

“I didn’t have to, Sans. I wanted to. I know you worry about it a lot—Grillby and I talked a bit while I was there—and I wanted to make sure you had less stress in your life. That’s also why I made certain that you still went to work while you were… not all there. No one really noticed.”

Skepticism burns its way through Sans’ ribs. “no one noticed that i was sleepwalking.”

“I mean,” Papyrus says, “I was accompanying you throughout both days. I thought you were just tired from sleeping poorly, and I wanted to help. You’d been waking up a lot from night terrors just prior to this further development, so… I thought this was just an extension of that, and I hadn’t been awake when they had happened.”

“mmh,” Sans grunts. “well, if nobody noticed and it didn’t impact the money… that’s fine, i guess.” He gives Papyrus a weak smile. “thanks, bro. don’t know what i’d do without you.”

“I don’t either,” Papyrus says. “But there’s no need to worry about it! I don’t intend to leave you. However! I do think it would be a good idea for me to start looking into these strange dreams.”

“what do you mean?” Sans asks, tearing open a ketchup packet and emptying it on his burger.

“Well, they must have some external source. Night terrors are common for you, but what you’ve described seems to be a type of magically-induced dream that forces you to forget things, if I’m remembering what you told me correctly.”

“yeah,” Sans replies, flushing slightly. He’d neglected to tell his brother about the arousal, about possibly not wanting these dreams to stop, but if it’s bothering Papyrus this much… Sans isn’t going to stop him. He squirts several more packets onto the fries, then sets the rest aside in the top half of the take-out container for later.

“So clearly it must be someone with magic that’s making you feel this way,” Papyrus concludes. “And I intend to find out who.”

“okay, bro,” the smaller skeleton replies between fries. “knock yourself out.”

Papyrus finishes his spaghetti in silence, then goes to wash the plate as Sans finishes his own meal. Once that’s done, Sans puts the take-out box in the trash and the ketchup packets in the fridge, save for one that he selects to consume then and there.

His taller brother looks at him expectantly.

“need something from me, bro?”

“I need you to come with me to gauge your reactions to the people involved. I’ve agreed to meet the first person in this mystery in Waterfall, and there’s no time like the present!”

“oh.” Sans blinks slowly. “i guess not.”

By the time Sans realizes what’s going on, Papyrus has all but dragged him out the door.


	2. quiet water

**Notes for the Chapter:**

> happy new year ya sinners. you guys are all great

“papyrus.”

“Yes?”

“isn’t this undyne’s place?” Sans would be surprised if it wasn’t, considering the house’s resemblance to its presumed owner. Papyrus is poised to knock, facing the door, but pauses to answer Sans’ question.

“Well, yes. She doesn’t really live here much anymore, considering she’s in Hotland or New Home between her two jobs most of the time, but sometimes she comes back on the weekends. And I asked her to so that we could have some privacy. I’d rather not bring Alphys into this just yet.” 

“you think there’s a possibility that undyne is doing this? i feel like i’m missing something.”

“No, absolutely not! But she might have more insight into the situation than I do. She does know more than me about the magical capabilities of our friends who are also our potential suspects.” 

Sans shoves his hands into the pockets of his hoodie. “why are our friends the only potential suspects?”

Papyrus looks like he’s been about to knock on the door for at least a few minutes now, but he finally faces Sans when he responds this time. “No one else would be strong enough. I’m almost certain that something like that would require expert-level control over one’s magic. But I want to talk to Undyne to be sure one way or the other.”

“ok,” Sans replies, and Papyrus turns back and raps on the door. 

Undyne opens it almost immediately, making Sans wonder how long she’s been waiting there, and if she’s heard any of their conversation. “Hey, guys! Wasn’t exactly, uh, expecting anybody today.” She grimaces, slightly. Probably expecting a day at home with Alphys, and Sans can’t bring himself to prioritize himself over Undyne’s happiness. Before she can continue, Sans tugs on Papyrus’ wrist.

“hey, bro, come on. let’s go home. i don’t want to bug anybody with this.” 

Papyrus doesn’t budge an inch. “Sans, I have already asked Undyne to come all the way back to Waterfall for this.” He tugs back on his arm, throwing Sans a little off balance. While his older brother tries to stabilize and shake off the dizziness, Papyrus continues, “Besides, blowing off your issues like they are no big deal is just going to make them a bigger deal later on.” 

Sans guesses that sounds reasonable enough, but looks to Undyne just in case she seems to think otherwise. She shrugs. “Yeah, I wouldn’t have come if I actually had better things to do. I’d love to spend the day with Alphys eating ramen cups, but if you need my help, that’s definitely more important. So come inside and tell me what’s bothering you. I’ll make some tea.”

Papyrus leads the way and Sans follows him in, both taking a seat at Undyne’s kitchen table. She must have been preparing for this moment, as the kettle is already out and on the stove. “What kind of tea would you like?” she asks. Sans notices with a stab of melancholy in his heart that Undyne no longer has golden flower tea.

“whatever’s fine,” he replies, and Papyrus nods his assent. Undyne pulls out three cups from her cupboard and starts working on the hot drinks. “actually, uh, i’ll be back in a few. need to clear my head.” 

“Okay. Water’s still boiling anyway. Try to be back soon, though.”  

Sans barely manages to stand up before becoming lightheaded, and collapses back into his seat. “maybe sooner than i thought,” he replies. “i don’t feel so great." 

Undyne looks back at Papyrus with concern. “Is this normal?”

The fear is back in his brother’s eyes. Sans regrets even trying to stand up, but Papyrus’ hands gently propping him upright help him to focus. Maybe he can try physical contact to ground himself in the future. “Not at all. But at this point, I am not sure anything in this situation can be called normal.”

“thanks, bro,” Sans murmurs. Papyrus nods at him and smiles. The kettle starts screeching, and Undyne breathes a sigh that sounds relieved as she pours it out all at once between the three cups as though watering flowers, splattering hot water all over the counter. It doesn’t seem to bother her, as she brings the mugs over to the two skeletons and sets her own down opposite Sans without so much as looking twice at the steaming countertop.

“So. What’s up?” Undyne bounces the teabag in the cup impatiently, the string wrapped around her first two fingers, as though willing it to steep faster. Sans stares down at his own cup, the water slowly turning a darker shade. 

“well, uh. i’ve been having these… weird dreams. i used to have nightmares pretty often, but these seem to have completely replaced them. in them, i’m… restrained in every way. tied up or something, and i can’t use my magic. i can’t think straight at the beginning, and then a light shows up, and i look at it, then i can’t think at all. and when i look at the light i start… forgetting things. when i wake up i still can’t remember them. and, uh, i guess there’s a voice, too. i can never understand it or tell who it belongs to, just that it’s deep and soothing and probably manufactured now that i think about it. and there’s no way to get them to… not show up, i guess, other than papyrus being there with me while i sleep.”

As Sans speaks, Undyne’s grip on the handle of her mug tightens. She stops forcing the teabag to bob in the water, deciding instead to start drinking the still-steaming water with a fierce eye, never breaking contact with Sans. When she finishes several gulps of her tea, she sets the half-full mug down carefully. Sans isn’t sure whether it’s because she’s forcing herself to restrain her rage, or if she just didn’t want to startle the skeletons. Whatever the case, he’s grateful.

“Yeah, someone’s messing with you,” Undyne confirms. “What have you been forgetting?”

“memories of the past,” Sans says, and it isn’t completely a lie, but everything from this timeline has been left perfectly intact.

“That’s unsettling. Do you have any idea why someone would want to do this to you? Or does it seem completely out of the blue?”

Sans shrugs. “no clue. i always feel safe while they’re happening, too. so whoever it is doesn’t want me to worry about it, at least not in the moment.”

Papyrus sighs. “Sans, you’re leaving out one of the most important parts." 

“what’s that, bro?”

“That the dreams have been making you completely lose track of time,” he says, and Undyne recoils slightly, staring at Papyrus.

“maybe you should tell this part, then. i don’t know much about it.” He shrugs, perpetual grin widening slightly at the half-joke. Papyrus sighs, which is… something, at least. Sans’ shoulders dip slightly as he exhales. Even if nothing else is going right, at least his brother is acting a little more like himself for now. 

“Well,” Papyrus starts, “on Wednesday I noticed that Sans had woken up unusually early, over thirty minutes before his sentry duty.”

Undyne puts her hand up to interrupt. “Hang on. I thought we didn’t need that position anymore.”

“Queen Toriel decided to continue to station Sans outside the ruins so that he could watch for newcomers,” Papyrus states. “But only in the morning. I believe there’s someone else responsible for that in the afternoon.”

“we’d have a hard time making ends meet without both jobs,” Sans adds. “i’d mentioned my financial situation to tori a few times before. i’m pretty sure she knows i’d have a hard time with anything other than what i’m doing now, though, so she kept the position around. and it does actually serve a decent purpose.”

“Okay,” Undyne says. “So Sans is awake more than thirty minutes before his job. I’d like to say that’s typical, but having been his direct supervisor before, it was unusual to see him awake thirty minutes after his shift started. Go on.” Sans feels like shit about his physical capabilities and puts his head down on the table, tucked in between his arms to block out the light.

“So, naturally, I try to strike up some friendly conversation, asking him what’s going on. I didn’t get a response, and he looked like he wasn’t really awake. So, naturally, I left him to wake up of his own accord for about twenty minutes, then re-entered when I would normally try to wake him up. He was fully dressed and just sort of… standing in the middle of his room.”

Chills run down Sans’ spine.

“I thought maybe he’d forgotten what he was doing, and I noticed how hunched and tired he looked,” Papyrus continues. “So I assumed he’d just woken up from a nightmare or something, or had slept very poorly from a night full of them when I hadn’t been awake to notice, and I helped guide him to his post since he was moving so slowly. I was going to take a short break to fulfill my duties to the flowers, but Sans was so sluggish that I felt it necessary to prioritize an important citizen of the Underground over some plants.”

“Which is why I didn’t see you that morning,” Undyne says, nodding. “Then?”

“After an uneventful morning, I walked him over to his hot dog stand in Hotland. Since I can’t travel as quickly as he does and he didn’t seem able to use his “shortcuts,” we got a ride from the riverboatperson and I stayed with him until that shift was also over. He was able to put the sausages in the buns, and I accepted and counted out the money. Thursday was fine, he seemed to be doing well, so I didn’t think to ask about it. Then on Friday the entire ordeal happened again, and I started to worry.”

“And you don’t remember any of this?” Undyne seems to have turned to Sans, if the direction her voice is moving is any indication. He shakes his head between his arms. “Hey!” she yells, slapping her palm against the table. Sans shoots up, breathing uneven and eyes wide.

“that seemed unnecessary,” he says.

“We can’t have you slacking off while we’re trying to figure out what’s wrong with you!” she snarls, and the fear paralyzes him. “So try to stay awake!”

Sans slouches in his chair, unfrozen but disappointed with himself for letting others down. He just wants to leave already and stop bothering her. “Undyne,” Papyrus says, looking at his brother, “I don’t think he was sleeping. Or trying to. Sometimes it just takes a lot of emotional energy for him to participate in a conversation.”

“Oh,” she says, and when Sans looks up he can see her mentally replace him with Alphys, then quake with disgust at her actions. “I’m so sorry. I didn’t mean—uh—Sans, you know I think you’re pretty cool, right? Like… I… I don’t know. I’m really worried about you and if you’re… unresponsive it makes it so I can’t do as much to help you. But if you need space, uh, feel free to… do what you need to do. I just don’t want you to feel like I don’t… think you’re worth this, or something. We definitely wouldn’t be here if you weren’t worth our concern.”

The smaller skeleton nods, settling back down into a less tense state. “thanks. for the apology and for being here. you can get back to business now, though.”

“Right.” Undyne clears her throat. “About how long are the dreams, do you think?”

Sans struggles to recall anything about the time surrounding them. “they feel really long, but that might be because most of my nightmares are very…”

He pauses when a phantom pain slashes across his chest.

_“hey, papyrus, do you want anything?”_

 Sans clutches at his shirt, wishing that pressure would stop the ache. “…fast-paced,” he finishes. “the dreams are very slow in comparison. and i only have one of them a night.” 

“You okay?” Undyne asks.

“fine. don’t worry about it. just an old wound coming back to bite me." 

“Sans…” Papyrus looks concerned. “I thought you’d always had 1HP.”

Sans’ smile falters. “yeah, i thought so too, bro. but you know how it is.”

Papyrus uncomfortably rubs his neck and for a moment Sans thinks that Papyrus might know how it is a little more than he would like. 

“anyway, i’m ok. let’s just keep going." 

“You only have one of them a night,” Undyne resumes. “Are you ever asked to speak?”

Sans shakes his head. “and i usually do have conversations in my nightmares.” Undyne looks at Papyrus for confirmation.

“He does usually cry out when something bad is happening in a dream, though not loudly,” he says. Sans is slightly relieved knowing he probably isn’t waking his brother up with his nightmares. “I’ve had to listen for him if I suspected it was the case. But on those days… he didn’t speak at all, not even when prompted. That usually only happens if he’s too tired to comprehend anything, but it was… clear he could understand actions. Once I got him going with the hot dogs he was capable of continuing the process for hours without verbal input.”

“So he couldn’t hear you, either.” Undyne’s eye narrows, and she props her elbows on the table, interlacing her fingers and bringing them to her mouth. Sans gets the distinct impression that she is looking through him rather than at him, so he turns his gaze to Papyrus.

“It did not seem so, no. His visual focus appeared extremely poor, as well. It is possible that he could not actually see anything and was functioning entirely on muscle memory.”

“Can you ever move in the dreams?”

“nope. the restraints are never lifted, and dream-me never has a problem with that.”

“Interesting.” Undyne places her palms on the table—more gently this time—and straightens her back, looking between the two skeletons. “So. What I’m getting from this is the following: During the day, it’s very likely that Sans is still dreaming. There’s a nearly complete separation between his body and mind in that time, and his body is only capable of performing routines or repetitive tasks like getting his clothes on and putting sausages in hot dog buns. And his mind isn’t capable of independently fighting back.”

“makes sense,” Sans replies. “does that mean anything?”

The former captain sighs. “It means I’ve got a lot of reading to do. For now, uh, Papyrus, if you notice him acting funny, try to wake him up, maybe? And if he lashes out, just make sure you don’t hurt him, you don’t get hurt, and he doesn’t hurt himself. Finding out what’s going on isn’t as important as your collective health. I’ll get back to you guys when I know more. And maybe start asking around. This sort of thing might be up Alphys’ alley.”

“Thanks, Undyne,” Papyrus says. “Sans, it’s probably for the best that we get home.”

“yeah,” he says. “don’t worry. i know a shortcut.”

 

Sans and Papyrus return to their home a little more quickly than the latter might have preferred, given how ill he looks. “Sans, why do your shortcuts always make me feel nauseated?”

“i dunno, bro. you just have to get used to ‘em, i guess.”

Papyrus shakes his head vigorously, then crosses his arms, staring at the floor and tapping his foot.

“something on your mind, bro?”

“It’s what Undyne said. That this situation is one with which Alphys might be familiar.”

“uh, i think she might’ve been talking about mew mew kissy cutie.”

“Regardless,” he says, frowning, “I would like to question her first. Have you not said yourself that there is much she has not revealed?”

Sans falls silent. He doesn’t know much of what Alphys has been up to since becoming the Royal Scientist, but he has heard that she isn’t responding to letters about questions regarding the monsters she’d taken in that had fallen. He understands not wanting to answer questions, on some level. Not wanting to hurt people with what you know.

But it does bother him a little, and he agrees that there are other things she could be hiding, so he gives an almost imperceptible nod. His brother catches every movement he makes when they’re together, ever-observant, so he’s satisfied with the answer. “Good. We’ll be heading out for Hotland tomorrow, then.”

“sounds good.” He’s not sure if it’s from the magic or all the talking or being exhausted, but he has a headache banging against the front of his skull.

Papyrus heads to the kitchen to start making dinner, so Sans lies down on the couch and closes his eyes, hoping it would go away.

It goes away completely after only a few seconds, replaced by a darkness that swallows him whole and spits him out bound and needy again, voice in his ear, gentle stimulation on his pelvis that just begs for thoughtless grinding. As he starts moving his hips as much as he can, the light blinks into existence, and his name is being whispered, but the longer he listens the more it sounds like Papyrus and now he’s shaking and—

“Sans!” He opens his eyes. He’s on the couch. It’s been hours. The spaghetti is cold. “Sans, I’m sorry. I didn’t realize.” He lets the pleading fade into the background as he hugs his brother, trying not to think about the steady thrum between his shorts.


	3. here we are

Papyrus stays with Sans and watches over him the rest of the night. He doesn’t know whether or not his brother sleeps, because his brother’s sleep schedule is wildly irregular in the first place and he won’t sleep if he thinks there’s something better for him to be doing than resting.

At least, Sans has thought more than once, at least he knows how to do it on his own, now.

His mind while asleep this night is mostly void, as much of the time spent sleeping around Papyrus has been. But he does have a single dream just before waking, neither the malignant magically-induced memory loss dreams nor the nightmares he’d grown accustomed to.

No, this is a dream he hasn’t had in a very long time, buried under guilt and fear and shame.

The iteration of Papyrus that resides in this dream starts him off by nibbling at his clavicle with one ungloved thumb rubbing circles into his soul. Like all dreams, this starts in media res, so Sans has apparently already gone to the trouble of summoning himself something to work with.

Or, it summoned itself and he let it happen, as was often the case.

His brother’s hand brushes against his ribcage, and Sans lets out a soft moan. The contact is enough to drive him up the wall already, if only because Papyrus has been so slow and careful with things for whatever reason. Sans wishes he would be rougher, just give him a little more friction, but if this was his dream, would that mean that he enjoyed being teased?

He didn’t know. Wasn’t really thinking about it much at the moment.

Papyrus keeps one thumb on Sans’ soul and starts rubbing the other against the head of his cock, turning his head toward the soft blue glow, and that’s when Sans wakes up.

Sans had thought about this scenario in a few different contexts before. First, the obvious: though his brother was of age, and had been for some time, Sans suspected his brother had either no knowledge of sexual pursuits or no interest in pursuing said knowledge. Considering how things had gone with the human, at least on some level, it was entirely possible that he didn’t experience romantic or sexual attraction.

Second, that while nowhere near the taboo that surfaced among humans, it wasn’t exactly encouraged for siblings to copulate. It wasn’t illegal, sure, but it also wasn’t… standard behavior. Family bonds and romantic bonds were, for the most part, expected to be separate.

Third, finally, how would Papyrus be able to give him a blowjob if he didn’t even have lips? Basic knowledge of anatomy, come on, Sans, think for a minute.

Sans is so preoccupied by his thoughts upon waking that it takes him a lot longer than he would have liked to realize that he just had an erotic dream about his brother, and now there’s a magical strain in his pants that he associates all too strongly with arousal.

His brother is still in bed with him, which is less than ideal.

His brother is awake, which is even worse.

“Are you alright?” Papyrus asks, and that’s the worst of all.

“yeah, bro, just… had a dream. not one of the bad ones.” He checks himself—no feeling that he’s forgotten something, which always comes with the other dreams, and no bone-rattling terror overtaking his whole being. Seems pretty reasonable to him.

Well, other than the tension in his pelvis, but that can be… ignored, for the time being.

Papyrus lights up when he hears the news. “Excellent! I, the Great Papyrus, have managed to ward off both nightmares and foul dreams for the entire night!”

“wait, it’s morning already?”

“Yes!” his brother replies with undue enthusiasm. “Perhaps with further prolonged contact, your condition will continue to improve!”

“that’s great, bro,” Sans says, shifting a little in his brother’s embrace, “but, uh, i need some alone time right now, actually.”

“I understand,” Papyrus says, patting his brother’s iliac spine, which immediately causes Sans to freeze up. Papyrus doesn’t seem to notice the reaction as he stands to leave. “I knew that kind of moaning wasn’t the type to come from fear.”

“oh god, i’m so sorry,” Sans says, covering his face with his hands. “i’m so gross and—“

“Sans.” His brother’s voice is stern, as though he were the older one. “I may not understand a lot of things. I still have a lot to learn. But I know that what you’re experiencing is not something that should cause you shame. It happens to most beings, including me! So, if it is a phenomenon that befalls even myself, there is no shame in it. I promise you. And you need not feel guilty about it, even if it takes place while I am near you.” He pauses for a moment. “I understand that you probably want to relieve this tension, so I will be taking my leave. Make sure you clean yourself up and come downstairs when you’re finished.” Papyrus turns to his brother and wags his finger at him. “And don’t let yourself fall back to sleep!”

“i’ll do my best, bro,” Sans says, and Papyrus nods at him and leaves Sans alone in his room.

He tries his best to think about someone other than Papyrus when he summons up his cock, but as he runs his own thumb over the head he can’t think of anyone else. His hands don’t even feel like his own, and with skeletal fingers and such a delicate touch it’s not like they could be anyone else’s but his brother’s. He runs two fingers over his iliac spine where Papyrus touched him, wonders if he’d meant to do that. Probably not. But at least the first point is crossed off his list of “reasons to feel bad about wanting to bone Papyrus.” Reason two can be pushed aside for the time being, and reason three isn’t relevant here anymore. He lets his hand dip down so that he can rub his ilium, other thumb still brushing across his now-leaking head.

A faraway part of him recalls that now that he’s out of the dream, now that it isn’t Papyrus stimulating him, he can go at his own pace, and in that moment the stimulation speeds up more than is truly safe or comfortable and he starts to fuck his hand, biting back any further noises so he doesn’t bother his brother any more than he already has. He prefers it a little rough.

As he quickens his pace, he can feel his mind start to drift, and _oh,_ that’s something that’s never turned him on before, and the breath he lets out in response is shaky and uncertain and heavy. It’s hard, being quiet, when he’s so unused to the concept.

Maybe… Maybe a whisper wouldn’t hurt.

“ah,” he moans, near-silently, stroking his length even faster than before. His hand is moving on its own now, which sends even more magic rushing down to his cock. “g-god. yeah. just like that. mm…” His spare hand can do nothing but grasp in futility at the unyielding mattress, his legs squirming as it builds. “oh, god, p-papyrus. please. please let me…”

His breathing is uneven and ragged, his eyes open but unseeing. He can’t think of anything but the friction and how he can’t think of anything but the friction, which turns him on even more and sends him spiraling even higher, tighter, tighter, like a coiled spring—

His orgasm shakes the bed, shakes him to his core, and if his eyes were open he still wouldn’t see anything for how overwhelming the pleasure has become. Even as he lets go his hand refuses to stop moving, wringing him dry, pulling every last drop of pleasure from him until he’s so exhausted he can’t even maintain the magic required to keep his cock around and it dissipates.

Sans gives a handjob to the air where his dick used to be for several seconds before he manages to stop himself and relax, taking a deep breath and making sure his eyes are open so he doesn’t fall asleep again. He sits up, sheds his clothes (god, he didn’t even get his clothes off before he started this mess?) and tosses them all in the laundry basket Papyrus has put in his room for easier transport. After all, his brother is just going to end up doing it anyway. Might as well make his job easier. Following that, he dons a new shirt and shorts and makes his way downstairs.

“You’re finished?” Papyrus remarks. Sans nods, a slight flush creeping across his cheekbones. He hasn’t showered, but it’s not worth it, really. Wouldn’t make him feel any cleaner.

“yeah. what are we up to today?”

“Once we’re done eating, we’ll drop by Alphys’ lab and see if she’s got any information one way or the other.” Papyrus is providing alfredo as an alternative to spaghetti sauce today. He has some garlic bread ready, too. He’s really started shaping up with this cooking thing, if Sans is honest. Even if Undyne isn’t giving him lessons all that often anymore.

The brothers eat in relative silence, Sans too ashamed to say anything and Papyrus seeming to be lost in thought. He keeps looking at Sans, but not truly staring at him in a way Sans finds customary. It’s entirely possible, the shorter brother thinks, that Papyrus is just spacing out in his general direction.

When Sans is finished, Papyrus takes his plate and puts it in the sink with his own. “I’ll wash these while you get dressed the rest of the way.”

“ok. do you want to take a shortcut?”

Papyrus sighs. “Not especially. Let’s just go get a ride from the river person. It would be less exhausting for you, anyway.”

He nods and starts heading upstairs to get shoes and a sweater on. “ok.”

When he returns, Papyrus is already done and ready to go. “Are you ready, Sans?”

The older brother nods. “yeah. let’s go.”

The walk through Snowdin is fairly uneventful. The river person is present on their boat, humming softly to themselves and seems to brighten up upon seeing the brothers. “Hello. Would you care for a ride?”

“That would be excellent,” Papyrus says. “To Hotland, if you don’t mind.”

“No trouble at all,” they say as the pair boards the boat. “I love to ride in my boat. And I love to talk.” The boat begins moving on its own, as it always seems to. “Have you heard the news?”

“What news?” Papyrus asks.

“There’s a mystery,” the river person says. “Someone using magic for illicit purposes. Tra la la.”

“yeah,” Sans replies. “we’re actually, uh, looking for them. i’m… kind of the victim, actually.”

“My condolences.” They look ahead toward Hotland, which is already rapidly approaching. “Seems very mixed up.”

“yeah.” He’s a little surprised that word travels that quickly.

“Your boat is very fast,” Papyrus remarks as it comes up to the shore.

“Thank you. Come again any time.”

“We’ll probably be back when we need to get home,” the taller brother says. “Thank you too.”

With that, they disembark and make a beeline for the lab. Papyrus moves much more quickly than Sans, and when his brother can’t keep pace, he picks up Sans and carries him the rest of the way to the lab.

“bro,” he says, “isn’t this a little much?”

“There’s no time to lose. I would like to get this resolved as quickly and efficiently as possible!”

“uh. ok.” Sans can’t really think of any way to argue with his brother, or any reason to, so he just leans into Papyrus’ chest and closes his eyes for a moment.

When his brother lets him down, they’re at the door, where Papyrus is already knocking. Better to get things over with, Sans supposes.

“Uh, hello?” Alphys’ voice comes from the other side of the door. “Oh, hi! Wasn’t expecting you guys today.” The lab doors open. “Do you need something?”

“Information,” Papyrus says. His face is completely stoic, and it seems to be unsettling Alphys as much as it is Sans, because she shivers and takes a step back.

“S-sure. Come on in.” She’s shaking as she allows them into her lab, so Sans hangs back a bit.

“this isn’t about the dte machine,” he whispers, and her shoulders almost immediately go slack as she exhales with a smile.

“Oh. Good,” she says. “I was, uh, a little worried there. That… you know. You’d…”

Sans shrugs. “i don’t know how much papyrus knows about him at all. he knows i used to help out with the former royal scientist alongside you. hasn’t ever given any indication of knowing anything more than that, though.”

Papyrus stops. “Sans. I can hear you whispering behind my back.”

“don’t worry about it, bro, it was just me… making sure dr. alphys here knew that we weren’t going to ask about her super top-secret experiments.”

“Unless,” Papyrus says, turning on his heel and taking a step toward the shorter monsters, forcing them to step back, “this is a super top-secret experiment. It could be anyone, Sans.”

“What’s, uh, what’s going on?” Alphys turns to Sans. “Is something wrong?”

“in a manner of speaking,” he says.

Papyrus huffs in response. “There is absolutely something wrong! Sans is having awful dreams that are erasing his memories. And in those dreams, there is a manufactured voice that whispers to him and he never remembers what it says.”

“That sounds terrible!”

“Does it, Dr. Alphys?” His eyes narrow. Sans doesn’t like where this is going. “Or does it sound… maybe a little too similar to something you enjoy? Someone doing exactly what you want with no memory of it? But it’s a little more perfect than even that, isn’t it?”

“What are you even talking about—“ Alphys starts, and before she can even finish her question, Papyrus has pulled out his phone and pressed a button.

From Alphys’ pocket, the Mew Mew Kissy Cutie theme song starts playing, and her eyes, too, narrow. “You don’t think I would…”

“I don’t know what you would and wouldn’t do,” Papyrus says, ending his call. The muffled music stops almost immediately. “I don’t know what you do or what you have done, other than making Mettaton and hang out with Undyne and watching anime. Emptying Sans’ mind could also be on the list of things you’ve done.”

As Papyrus speaks, Sans feels his knees go a little weak. His body tingles, and his head grows fuzzy, like he’s in the dark room again. When he shifts back into awareness, he’s left with a nagging feeling.

He’s lost something else. Something new has been forgotten. And he wasn’t asleep.

Sans collapses into a sitting position. Papyrus’ head snaps from staring down the doctor to Sans. “Are you okay?”

He laughs, but it comes out weak. “just lost something new.”

Papyrus sits on the floor next to his brother, putting his hand on Sans’ shoulder. “Sans, I’m so sorry.” His voice is gentle, and Sans leans into the touch. “I… was so preoccupied I didn’t… I’m sorry. Dr. Alphys. Please sit so we can talk about this.”

Alphys sits on the floor across from Papyrus. “So. You think I did this.”

“I think it’s possible,” he says. “But you’re not the only suspect. I would just prefer to cross you off the list first, if it’s not you, so we might enlist your help trying to catch the culprit. We talked to Undyne about it yesterday.”

“Oh,” Alphys says. “So that’s what that was about. Okay. Well. What do you need to know?”

“That is the question, isn’t it? Maybe just… tell us what you know about this kind of magic.”

“yeah,” Sans adds. “i’ve known you for a long time, too, so if you’re not telling the truth, i’ll be able to tell. so make sure you tell us everything you know, and don’t mess anything up with me in the process, or papyrus will notice.”

“That’s true!” Papyrus says. “I will notice if anything is wrong with Sans.”

“Okay.” She shrugs. “Well. I don’t know much about this kind of magic, because I can never read for very long before… uh… heh.” She turns bright red. “Well. Anyway. What I do know is that there are multiple different methods, but across the board it’s very taxing on the user. Especially long-distance, it would take an immense amount of concentration and energy to maintain all day. I mean, I’ve tried it a couple of times on myself, and that was easy enough, but I can’t seem to figure out the nuances, since I can’t read about it, and I don’t think I’d be able to keep it up like that. I’m too busy. And lethargic.”

It could be used on oneself. Time to file that away to consider later. Sans studies his friend’s face and posture. “she’s not lying, bro,” he says. “actually, looks a little upset that she couldn’t be a suspect because she can’t do it. she’s just not physically capable. so, uh, do you have any ideas who would be, alphys?”

“Well,” she says, “uh, a Boss Monster would, um, definitely be capable of that kind of power.” She flushes again, then raises her eyebrows at Sans. “I would also guess that it might be something that our mutual friend may be able to do. Um. Other suggestions include Grillby because he has a motive and an undetermined level of power, Mettaton because that’s something he’s interested in and would certainly be powerful enough, and, uh, anyone else sufficiently determined that you’ve somehow pissed off.”

The last point seems to catch Papyrus’ attention. “Oh. Is that all?”

“Should be, yeah. Do you, uh… do you guys want to watch some anime while you’re here? I can make you some cups of noodles.”

Papyrus looks to Sans, who shrugs. “sure. why not?” Sans’ question is answered almost immediately when he sees what anime she makes a beeline for. “uh, wait, alphys, isn’t this the one with the, uh, the brothers? that… uh?”

Alphys stares him dead in the eyes and says, “Yes, Sans. Yes it is.”

Sans doesn’t see how Papyrus reacts, because he’s too busy covering his face and regretting opening up to Alphys about anything involving his personal life.

“Sans, are you okay?” Papyrus asks.

“yeah, bro. i’m. i’m fine. let’s just. sit down and watch this great show,” he replies, his voice muffled by his hands.

“Sounds good!”

He's going to have a lot of explaining to do.


	4. memory

**Notes for the Chapter:**

> Okay, so this has come up a couple of times and I wanted to make a note of it: this is taking place in the pre-True Pacifist ending, which means it's still a Neutral ending. Frisk has left the underground for the time being, and Asgore is dead. Basically just everything that happens right before going back to give Alphys the letter to get the True Pacifist ending.
> 
> That said, I'm flattered that you guys are already coming up with so many ideas about what could be going on. I won't be answering who it is until later, since I'd like to keep it a mystery, but I do like seeing the different theories a lot! So, thank you. I did not expect this to get as popular as it has. I'll try to keep the chapters coming in the days to come.
> 
> Romance coming up soon.

The anime night had gone… surprisingly well. There had been no commentary from Papyrus on the whole… situation, which made Sans feel a little better. Papyrus had enjoyed himself, and Sans had felt himself going along with things and liking it as well.

Since he’d shown improvement in the dream department, Papyrus had decided it would be better to let him sleep alone again so there wouldn’t be any potentially embarrassing situations in the morning. He’d informed Sans that he’d be over if he started to worry about his condition, and potentially checking in on him every once in a while since he had quite a bit to do that night. While Sans didn’t like the concept of his brother staying up all night, he knew Papyrus would do it whether he liked it or not, so he acquiesced.

But now… Now, none of that matters.

There’s a gentle stimulation on his ribs now as he stares deeply into the light. He can feel his magic start to build in his bones. He feels so strange, but… he also feels better than he’s ever remembered in his life, safer, warmer. Like nothing will hurt him here. His thoughts and memories, which so often betray him, have been softly drained away. He doesn’t know if the forgetting and the touches, so gentle and caring and safe, are supposed to turn him on, but they do all the same. They make him feel comfortable, and in his comfort he allows himself to let go and surrender to the blissful sensation of oblivion.

Forgetting things is erotic now, because to forget is to be safe and without pain and to surrender and to feel good. He doesn’t want these dreams to go away. Never wants them to stop.

He’s swaying gently, looking at the light, when he blinks awake and sees his brother’s silhouette in the low light from the open door. Papyrus’ hand is on him, shaking him, but as he sees his brother’s eyes open he stops the motion.

“Sans?” he murmurs. “Are you alright?”

“yeah, bro, i’m fine,” Sans replies. “are you?”

Papyrus nods. “I just had a bad feeling all of a sudden and I wanted to check up on you.”

Sans takes a moment to take stock of himself. Strangely enough, none of his memories had disappeared permanently this time. “i’m good, bro. don’t worry about me.”

“If you insist,” Papyrus says, sighing as he turns to leave.

“hey, uh, wait.”

“Yes?”

“are you still busy?”

Papyrus turns back to look at his brother. “Why?”

“i just figured… you know… might be worth it to try doing the, uh, sleeping in the same bed thing again. but maybe you should try sleeping too.”

His brother yawns and nods. “That… may be a good idea.” He lies down on the bed next to Sans, facing the ceiling, his body rigid as he closes his eyes. “Good night.”

“are you actually comfortable like that?” Sans asks, and Papyrus writhes a little.

“Well, on my bed, yes. On your bed… not especially.”

“here. try lying on your side.” Papyrus turns toward Sans. “and then c’mere.” The two scoot closer until they’re in embracing distance, then Sans wraps his arm around his brother’s ribcage. “there. and then you just… enjoy it. and let yourself drift off.” Talking like that gets him a little worked up, but he puts a quick mental clamp on that. No more sexual thoughts while his brother is in bed with him unless Papyrus initiates them. Papyrus pulls his brother close and shivers a little, though Sans knows it’s not from the cold. “um. is something up, bro?”

Papyrus doesn’t answer, just holds his brother a little tighter. “I’m sorry.”

“about what?”

“About not finding the culprit faster. About not being a good brother. I just don’t know how to… do all this. And I feel terrible for it.”

“papyrus, you’re a great brother,” Sans replies. “you’re trying your best, and i really appreciate it. nobody ever told you what to do, and you’re trying to figure it out anyway.”

“But I’m doing a terrible job,” he retorts. “The Alphys interrogation was a mess. I didn’t ask any actual questions that could have led to a solid conclusion. She still could have feasibly done something with the help of someone else, which I completely neglected to go into! For example, Mettaton. They’re close enough that he would consider it, right? And he has the power to be able to back it up.”

Sans mulls this over for a moment, then states, “motivation. there’s no reason for them to team up to make me forget. alphys might think it’s attractive, and would want to help me, but mettaton would need a bribe of some kind. and i don’t know if alphys has anything more to offer.”

“Helping you.” Papyrus’ grip loosens. “Sans, can you hear yourself talk?”

“what?”

“You just said that Alphys would want to help you. Which would imply that you believe that making you forget things is helping you.” He trembles, tightening his grip again, and something moist touches Sans’ skull where it contacts his brother’s. “What if you forgot me?”

There’s something inside Sans that says that he has, he’s forgotten terrible things that have happened to Papyrus and all he’s been left with is the feeling that something used to be there, something that made his gut wrench whenever he looked at his brother, and that there are still things there that he would give anything to forget, like watching his brother’s head tumble from his body and crumble to dust too many times to count, like a human who refused puzzles and stuck a knife between his ribs and pierced his soul before he could even think of capturing them.

“papyrus,” he says, settling on a response that is both a lie and truth as he embraces his brother a little tighter, “i could never forget you.”

The taller skeleton doesn’t respond in words, only pulls him closer. He’s shaking and crying and Sans can only give him a squeeze of solace to calm him. After a few minutes of silence, Papyrus’ sobbing winds down and only a few aftershocks of shudders remain. “I… Sans…” His voice is cracking, and he quakes again, falling silent.

“hey, relax. weren’t we trying to sleep?” Sans offers. “just close your eyes, ok?”

Papyrus obliges, though he still looks stiff. “We can talk more in the morning.”

“yeah. just let yourself drift off for now.” He rubs his hand gently over his brother’s spine, and Papyrus lets out a heavy contented sigh. There’s a tingle in his fingertips, then aqua sparks shoot up his brother’s back and Sans jerks his hand away. Papyrus goes limp on the bed, and a brief panic sets in before he realizes that his brother is still whole, not turning to dust and slipping away. Papyrus curls into him a little tighter, but as soon as he does his body relaxes again. So. Just asleep, then. Nothing to worry about.

Except, of course, that he just lost control of his magic, which is something that’s never happened before. He wonders if his grip on his memories is tied somehow to his magic. If forgetting is making him lose control. If he’s used any magic already that he hasn’t known about.

He clenches his eyes shut and tries to ignore the chill that runs down his spine.

 

Sans doesn’t tell his brother that he’s not in control of his magic, so the two go down to the river and take the boat to Hotland again. Sans is exhausted, sitting on the floor of the boat for the duration of the ride. His worry kept him from sleeping any longer, and though he’d gotten some rest from the dream he’d had, his anxiety wears him out.

He can’t even manage to get off the boat by himself, so his brother smiles at him and picks him up, resting Sans against his shoulder and making his way to the elevator. Papyrus is warm, somehow, and it’s easy for Sans to let his eyes close and rest in his brother’s arms.

He stirs again when he’s set down on the floor. “I’m sorry I’ve been so preoccupied lately, Queen Toriel… but there’s something wrong with Sans. And I was wondering if I could ask you a few questions.”

Sans opens his eyes. Papyrus has set him down in the corner as he waters the flowers. Toriel is sitting on her throne in the center, watching him circle her. “Of course, Papyrus. What do you need to know?”

The skeleton’s expression turns serious as he looks at the Queen. “How much do you care about Sans?”

Toriel considers, then looks down. “Quite a lot. I want the best for him that can be achieved.”

“And if you were to discover that you could help him using your magic…?”

“In a heartbeat,” she says. “What is this about?”

“Now then,” he continues, ignoring her question as he continues to pour water on the golden flowers, slowly circling the throne. Sans isn’t sure if he’s trying to be intimidating or not, but Toriel looks unsettled nonetheless. “How powerful are you, exactly?”

“Well… I am the only Boss Monster in the Underground, am I not?” She straightens a little, like she realizes she shouldn’t be intimidated by the skeleton watering flowers around her. “So… one would assume I am one of the most powerful monsters here.”

Papyrus nods. “Of course. And how powerful, specifically, is your magic that affects the mind?”

“W-well,” Toriel stutters, “not much is known about that category of magic at present, if I am correct? So it is not very strong.”

The skeleton stares at her, his eyes hard. “It’s certainly not as well-documented as physical magic, no, but I find it difficult to believe that a Queen of Monsters would have such a glaring weak spot when the base magic is not particularly complex to master and is an active part of the curriculum for young children learning magic. And are you not a teacher?”

Toriel shifts uncomfortably. “Yes, but I do not teach beyond the basics of either type of magic.”

“But you are very powerful with fire magic. And you could feasibly be very powerful with another kind of magic.”

“Just what do you think is going on?” the Queen demands, standing from her seat to meet Papyrus’ eyes. “I said that we could talk this morning. I was not expecting an interrogation!”

“Sans has been losing memories and everyone close to him is a suspect.” Papyrus’ voice is dangerously cool, nothing like his usual passionate tones. Sans hates it. He hates that something happening to him has affected his brother so much. “Especially someone as powerful as yourself, who would have the ability to enact something as intense as this.”

“And what would I have to gain?” Toriel, too, is cool now, her voice dropping.

“His loyalty. His affection. He believes what is happening to him is beneficial, that this is helping him. And you were noted friends, talking at length about your lives on each side of the door before you became Queen.”

“papyrus,” Sans interjects as he stands, “please stop. i don’t like seeing you like this.”

Papyrus frowns, then straightens. “I’ll have to determine another method, then. I’m sorry, Toriel. I’m just… very worried about Sans, and I need to find the culprit as soon as possible. If you believe you’re helping him by doing this, please just tell us.”

Toriel shakes her head. “I don’t know where I’d even start trying to make Sans forget things. I don’t know why I would. If there’s a reason that would help him, he hasn’t shared it with me.”

Papyrus turns to Sans, who nods. “yeah. i never told tori about… that.”

“Ah. Sorry to waste your time then, Toriel.” He shakes out his watering can to make sure all the water is out, then puts it down in the corner. “I’ll be dropping by tomorrow as well, but I… am quite preoccupied.”

Toriel waves her hand. “Do not worry about it. Sans should be your top priority at present. I do hope that he is alright soon. If there is anything I can do to help, please let me know.”

“Sure thing!” he says, and he’s back to the chipper mood Sans is used to. This is strange, and Sans hopes that it’ll stop soon. He chooses to say nothing for now.

“Well, I should be off,” Toriel says. “The school will not stay empty for long, since it is getting closer to time for things to start. I am sorry I could not help more.”

Papyrus says something else, probably along the lines of “It’s fine,” but Sans doesn’t catch it because his mind whites out before his brother even begins speaking. He falls to his knees as Toriel turns away, his legs quaking, and an erotic shudder runs through his body.

Another memory gone.

He gets back to his feet. Papyrus looks concerned, but he shakes his head. Not exactly something he wants to talk about right now. His brother offers his arms, and he decides to indulge. He’s not sure he can handle walking very far right now, so he stumbles into his brother and lets the embrace lift him up.

“I’m going to try to start getting the others to Snowdin instead,” Papyrus says. “I’m sorry this has been so rough on you. I love you.” 

It’s the last thing Sans can make out before he falls asleep.


	5. your best friend

Maybe he’d have an easier time resisting if the light wasn’t so warm.

It was more difficult for Sans to feel heat and cold than most, as he didn’t have the requisite organs or systems, but thankfully the magic that made him up allowed some of the sensation to pass through. Snowdin was cold, often piercingly so, and the warmth felt much better than the alternative. So, as much as he can while bound and half-aware, he moves closer to the light.

This time, to his surprise, the light moves closer to _him._

He wakes to find his brother pacing behind the couch, muttering. “…don’t know what we’re supposed to do. I haven’t been able to come up with good questions to ask this entire time, and I feel like I’m failing you. How are we going to stop this if I can’t manage to think of anything? What is the point in asking? They can lie, and I don’t have the ability to detect lies.”

“i think it’s more about seeing their reactions,” Sans replies, sitting up and facing his brother over the back of the couch. Papyrus blinks and takes a step back, his eyes wide for a moment before he settles. “if they look like they weren’t expecting someone to catch on, well, that’s a pretty good indicator. if they’re overly hostile when asked about things… if they won’t answer questions… that kind of thing. the questions matter less than the behavior in response to the questions.”

Papyrus nods. “That’s useful information, Sans. Thank you. And, I just had a thought. If I could perhaps get any information out of you while you were in one of those dreams, we might use it to our advantage. We could potentially determine what memories are going missing! It might be a little dangerous to not stop them immediately, but it’s possible that inquiry will halt further progress. It’s worth trying at least once, I think!”

“yeah, that sounds good. and i am still pretty tired, so… maybe i could just go back to bed.”

“Of course. Your nap was rather short, compared to your usual. Only about an hour or so. It might be a bit more conducive to hold the experiment in my room, since my bed is more comfortable. I’ll bring lunch up so you can eat afterward, though.”

“ok.” Sans hops off the couch and makes a beeline for his brother’s room. He hopes that Papyrus doesn’t ask him about his feelings. But, knowing Papyrus… he might get overenthusiastic and start asking about questions that he didn’t truly want answered. Sans shakes this off and tries not to think about it.

Taking his mind off the topic becomes much easier when he enters his brother’s room, because he notices something out of place. There’s almost nothing ever out of place in his brother’s room, so he’s suddenly concerned when he finds a book on the table next to Papyrus’ bed amidst his action figures. It’s one of the library’s, from the section about humans. Something about myths. There’s a bookmark tucked inside, and Sans opens to the marked page.

“The river Lethe,” the book says, “was one of five rivers in the underworld. When the waters of the Lethe were consumed, the drinker would lose all memory of their former life.”

Sans hears footsteps on the stairs and he’s not certain he really wants to read any further anyway, so he shuts the book and makes himself comfortable on his brother’s bed. Papyrus enters empty-handed, so he figures his brother had probably meant to bring leftovers up after he was finished.

Papyrus makes sure that Sans is comfortable before reaching in and stimulating his brother’s soul. Sans hadn’t realized how tense he’d been feeling, but it all melts away when his brother makes small, gentle massaging motions into his magical center.

He closes his eyes and the light comes back, of course it does, but he can still feel a hand massaging his soul and he thinks for a moment about how surreal this is before he hears someone far away start asking him questions. He can tell they’re questions because of the upward inflections at the end, but he can’t tell what’s being asked. At least, his conscious mind can’t, if the fact that he’s still somehow replying without knowing what he’s saying is any indication. The soul stimulation and looking at the light feels amazing, especially with the low drone of call-response in the background, and he’s content to let himself drift for a while.

He’s eventually pulled back into reality without any stimulus, which is odd. A quick check confirms he hasn’t lost any memories this time. His soul isn’t being touched anymore, and Papyrus looks like he’s focused on a spot on the bed, sitting beside Sans in a chair. His arms and shoulders are limp as he slouches. Sans notes that there’s a running tape recorder on the side of the bed. His brother must have thought Sans might want to hear what he said while he was under, which he appreciates.

“papyrus?” he asks, and his brother tilts his head up slightly to look at Sans. “what happened?”

Papyrus doesn’t look like he can see Sans at all. Doesn’t look like he can see anything, or at least, that he’s processing any information. “Asked some questions. You answered them all. I said I wished I knew what it felt like. You transferred it over to me somehow. Now I do.”

“are you going to forget anything?”

His brother’s expression turns dreamy. “I don’t know. It doesn’t matter to me.”

This bothers Sans, more than a little. Now he knows how Papyrus must have felt earlier. “uh. how are you feeling?”

Papyrus considers this for a while. “Peaceful. Warm.” A pause. “Aroused.”

Sans is already feeling a little turned on from the dream itself, but hearing his brother admit the same turns his lust up a few levels. He squeezes his eyes shut. It would be wrong to take advantage of his brother in a state like this. Sans sighs and opens his eyes again. “ok. i’m going to ask you a few more questions and then, if you can, i’d like for you to wake up, ok?” Papyrus nods, so he continues. “h-how much do you love me?”

“More than anyone else I’ve ever known,” Papyrus replies. “You’re the most important monster in the whole Underground to me.”

Sans shivers. He’s not sure he can follow up with anything else. Papyrus probably doesn’t feel romantic attraction at all. So he writes it off. “that’s, uh, that’s all, actually. so if you can wake up… go ahead and do that.”

Papyrus’ back straightens and he blinks a few times, re-orienting himself to the room. “Oh. Hello, Sans. You look more awake. Did you forget anything?”

“nope. you?”

The taller skeleton shakes his head. “I don’t think so. That felt… very unique. I’ll go grab the spaghetti, and then I can see if Flowey’s up for his talk today as well. Once that’s done we can replay the tape so you can hear what happened, and so I can figure out what happened after I went under.”He presses the stop button on the recorder.

Sans had forgotten about the tape, even though he’d noticed it only a few minutes ago. He’s glad, now, that he didn’t ask anything particularly incriminating. “two people in one day? that’s pretty intense.”

“Well, I’d like to get this matter settled as soon as possible,” Papyrus states. “I don’t like making you go through this, pleasant as it feels. I can… understand, now, why you thought it was helping. And, given the nature of the memories you lost—which, by the way, aren’t completely lost! They’re just inaccessible to your conscious mind—I don’t blame you for feeling that was an improvement, either. But it could be dangerous to keep it up, and you could start losing things that are crucial to your daily life, and I don’t want to risk that.” 

Sans nods. “i guess that makes sense. i can come down with you to eat, if you want.”

“That would probably be more convenient, if you feel like you can do that.”

Sans hops out of the bed in response. “ok. let’s go. i’m pretty hungry.”

Papyrus hasn’t moved yet, so Sans stops, turns to his brother, notes his downcast expression. “Sans?” he asks, his voice softer than the smaller skeleton expects.

“yeah, bro?”

“I… Never mind,” he says, and rushes past his brother down the stairs.

 

Lunch doesn’t take long, and not too far into the afternoon, Papyrus sets out to find Flowey, an entity with whom Sans is entirely unfamiliar.

Fortunately for their time constraints, Flowey is right outside their front door when Papyrus opens it. Sans is, understandably, unsettled by the sight of a flower with a face.

“This is Flowey.” Papyrus gestures toward the flower.

“Howdy!” Flowey says, and Sans thinks about how strange it is for a flower to say “howdy.”

“hey,” Sans replies, uncertain. “how, uh, how do you know my brother?”

“Oh, we’re the best of friends,” Flowey states, looking up at Papyrus, whose cheekbones tinge orange. “We talk about everything. Don’t we, Papyrus?”

Papyrus shrugs. “We do talk about a lot of things.”

“Anyway, I’m going to have this conversation about Sans’ health on one condition.” Papyrus looks shocked, like he hadn’t expected there to be any strings attached. “Papyrus, I think the facade’s gone on long enough. Once we’re done, you and Sans really need to have an honest and open talk about your feelings.” He winks and sticks his tongue out. “I can’t go inside your house, so I’ll meet you out by the Waterfall side of town. See you soon!” Without any further input from either of the skeletons, Flowey disappears into the ground.

“well, that was surreal,” Sans says, staring at the hole in the ground where Flowey once was. He feels a little unstable, and he leans onto the wall in an attempt to appear nonchalant as he rights himself.

“He takes some getting used to,” Papyrus replies. “We should head out there.”

“there’s something weird about him.” Papyrus doesn’t seem to notice Sans’ remark, as he continues out the door. “it’s… i don’t know how to describe it.”

“Which is why he’s a suspect.” Sans closes the door behind them and takes a few particularly long steps to catch up to his brother. “He’s… told me that you two haven’t always gotten along in the past. In the other timelines, I think is what he meant, considering your dreams. Do you remember anything about that?”

Sans shakes his head. “i’ve never encountered him before, and i don’t think any of the memories relating to him are missing. i guess i have no way of knowing, though.”

“Well, from what I determined based on what you told me while you were asleep, you only seem to remember the most traumatic parts of other timelines. So it’s possible that he never caused you that kind of distress.”

“yeah. that’s… possible.” Sans shrugs. “let’s just get this over with.”

The pair arrives in front of Flowey, who has already arrived at the stated Point B. “So! What is it that you needed from me, Papyrus?”

The taller skeleton sighs. “I just wanted to know approximately how powerful you are.”

“Oh, little old me? Well, I can’t do much. No more than any monster, for sure!” he says.

Papyrus looks to Sans, then back to Flowey, and sits down in front of the flower. “How much do you know about this kind of magic?”

Flowey laughs in a way that doesn’t seem appropriate to the situation somehow. “Oh, not much, but I don’t have to. After all, just knowing what sequences of words will make your head empty right out is all anybody would ever need, isn’t it, Sans?”

Sans feels dizzy, and the world fades out for a moment. When it comes back into focus, he’s lost another memory, he’s on his knees and staring at the ground, and he’s intensely turned on. “what the hell did you just do to me?” he asks, his voice shaky.

“Making a point,” Flowey replies. “I won’t plead innocence. I’ve been observing you for the person that’s casting the spell. But me, doing it myself? Ha! There’s no way I could ever manage that.”

“Why are you helping?” Papyrus asks, his eyes narrowed.

“Well, because it’s fun to watch. Why else? I’ve needed something this entertaining for a long time. Life down here gets awfully boring when you remember all the resets, after all!”

“So you’re willing to make my brother suffer for kicks?” Papyrus growls. Sans wants to put his hand up to calm the taller skeleton down, but he’s not sure he can move yet.

Flowey cackles. “Oh, don’t pretend like you didn’t just hear that he’s not suffering! This is helping him more than anything ever has before. He’s enjoying himself. Maybe you should too.” A giggle this time, lighter, with a touch of faux-innocence. “Now, don’t take this as some kind of statement that I actually know who I’m working with. But they wanted my help, and I was willing to oblige if it meant being able to have some fun for once. So I can’t point you in the right direction. And maybe I am kind of genuinely sorry about that.” He averts his eyes from Papyrus when the skeleton looks at him, frowning. “Because, you know, I actually… like you. You’re pretty cool. So if I knew who it was… I’d point you in their direction. But I can’t.”

“do you honestly believe this?” Sans asks Papyrus, but his brother scoots forward toward Flowey and doesn’t respond to him.

“We’re going to figure out who did this,” Papyrus says, and Flowey’s smile is one part what appears to be genuine sympathy and one part mischief.

“Well, if you figure it out, let me know,” he says. “Anyway, I assume you’re done? Now for my part of the bargain.”

With a sigh, Papyrus stands. He doesn’t look at his brother when he speaks. “Sans, um, I… have romantic feelings for you.”

Sans blinks. This has to be a dream. He blinks again, and the image doesn’t fade. “…really?”

“Yes.” He’s going orange in the face again, slowly turning away from Sans. He looks like he’s going to run at any moment. Flowey looks expectantly at Sans.

“i, uh.” He clears his throat, trying to get the words to come out right. “me too.” He’s still waiting for something to go wrong, for something to fail miserably. Maybe he’ll wake up in a few minutes. Maybe this was all just one long nightmare.

Papyrus turns back to him, examines his expression. He does his best to look earnest, and apparently it’s good enough, because he falls to his knees and hugs his brother tighter than ever before that Sans can remember.

“See?” the flower says, grinning. “This really did need to happen. I knew everything would work out alright. Anyway, I’ll be around!”

Sans doesn’t even care enough to watch Flowey disappear into the ground. He buries his face in Papyrus’ scarf and lets out a sob of relief. “i… i can’t believe…”

“Me neither,” Papyrus says. “Trying not to admit it and keep it inside made me feel so empty. But now… now my soul feels like it’s filling up. I love you so much.”

“i lllllll…” Sans starts, but there’s a flash through his mind and he shudders in his brother’s arms, barely holds back a moan as he loses another memory. “love you too, bro.”

“Did I do something?” Papyrus asks. “Oh, Sans, I’m so sorry. I don’t know what’s going on.”

“’s fine,” the shorter skeleton replies. “don’t worry about it. so, uh, what does this mean for us?”

“I don’t know. I think we should probably try listening to the tape first, and then we can discuss what’s in store for… well, us.”

“ok.” He wraps his arms around Papyrus’ neck, burying his face in his brother’s shoulder, and hopes that if this is a dream, that he’ll never wake.

**Notes for the Chapter:**

> the gay begins. i hope it'll meet all your expectations


	6. death by glamour

_“Hello. This is, um, Papyrus, Captain of the Royal Guard, on Monday, February eighth. I am presently twenty years old, and only six days short of a third of the way through my twenty-first year. I am making this recording because my brother, Sans, sentry and hot dog vendor, whose twenty-fourth birthday is in one month and nine days—“_

Sans pauses the recorder. “are you always this meticulous?” he asks.

“Yes,” Papyrus says. “I want to know exactly when things happened. And I also want to make sure I remember when your birthday is.”

“does this go on for much longer?”

“No.”

“ok.” He presses the play button again.

_“—has been suffering from a strange condition.”_

Papyrus gives Sans a look that could not possibly mean anything but “I told you so.” The recording continues.

_“He has been losing his memories because of a form of mind-altering magic that has been cast upon him. This recording is intended to document the conversation so that he may know what he has said while in one of the magically-induced dreams when questioned on what is happening.”_ There’s a slight shuffling, then Papyrus’ voice comes back, a little quieter. _“Sans, can you hear me?”_

_“yeah.”_ While the recording is clear, Sans himself is slightly difficult to understand, though it seems to be little more than the outcome of talking to any sleeptalking person.

_“How are you feeling?”_

_“good.”_

_“Can you elaborate a little more?”_

_“safe. warm. calm, i think. turned on. everything feels great.”_

_“Is it the soul stimulation that’s arousing you?”_

_“the light more than that.”_

_“Okay. Can you tell me a bit about the light?”_

_“it’s white and it pulsates. it used to blink all the way, but now it never really goes out. just gets brighter and darker. when i watch it, my thoughts stop, and sometimes i forget things. and forgetting feels… amazing.”_

_“Can you tell me about anything you’ve forgotten?”_

_“when i’m awake, i can’t remember the times i’ve been slashed through by a human while trying to defend the underground. the times a flower has ruined everything for everyone. the times i’ve died trying to protect you. i’ve watched you die more times than i can count, and i’ve tried my hardest to cling to you. but it always ends up reset. everything else fades into the distance, but the truly significant parts—the parts where terrible things happen, the parts where i fail—i carry those with me. or, at least, i did. the light has wiped those away. and it’s in the process of getting everything else. timelines where everyone died except me. timelines where they only killed you. there are a lot of things left.”_

The recorded Papyrus makes a thoughtful noise. _“So you’re only forgetting things from timelines that aren’t this one?”_

_“yeah.”_

_“And this has been helpful for you to forget.”_

_“yeah. no more night terrors, and it feels amazing to forget. i’ve started getting turned on when i do because of how good it feels.”_

_“Hm. That could be inconvenient. I assume you don’t want it to stop.”_

_“no.”_

_“This sounds a lot like an addiction… And there’s no guarantee they’ll stop at your past memories. This could go on until it consumes everything. I… I’m sorry, Sans, but I can’t allow this to continue.”_

_“mm. you’ve never felt it before.”_

_“You’re right, I haven’t. And I wish that I could, so I had a better idea of what’s happening to you. But there’s no real way for me to be able to feel the same way without finding the culprit—“_

_“that’s not true.”_

_“What?”_

The sound of sheets shuffling, then bone brushing against bone. _“do you want to feel it?”_

_“Y-yes?”_ Papyrus says, then he moans in a rather lewd manner. _“Oh, this feels… Mmmmm… What… How… I… Uh…”_ His words trail off, and Sans can hear him slump against the seat. A pause ensues that stretches out into what feels like eternity.

Then, “ _papyrus? what happened?”_

_“Asked some questions. You answered them all. I said I wished I knew what it felt like. You transferred it over to me somehow. Now I do.”_

Sans stops the recording. He doesn’t want to get even more aroused than he already is, even though his brother has admitted his feelings for him. “you can listen to the rest of this, bro. i’m getting kind of hungry. i’m gonna go have some chips, and i guess we can meet downstairs when you’re done with the tape.” Papyrus nods, so Sans heads through the door and down the stairs to give his brother some space.

It doesn’t take much longer for Papyrus to finish up the tape, and when he comes down the stairs, Sans has already eaten all the chips. Papyrus looks shaken, so Sans removes the empty bag from the couch and pats the seat next to him. “hey, bro. you ok? you look a little… rattled.” He grins, and Papyrus manages a smile.

“That’s the first pun I’ve heard you make in a long time.” He scoots a little closer to Sans. “I’m sorry this is taking so long.”

“it’s ok, bro. i actually feel… kind of hopeful,” Sans replies. “for the first time in a long time, things feel like they might be ok.”

“That’s good,” he says, but he still seems unsettled.

“is there anything i can do?”

Papyrus sighs. “That depends entirely on how much you are willing to do.”

Sans reaches over to his brother and pushes up the battle body, revealing Papyrus’ ribcage. He looks down at the soul inside, straining like his own has done so often before.

If Sans’ own experiences are anything to go by, Papyrus is hopelessly turned on. He reaches in to touch his brother’s soul, and the resulting brush against it makes Papyrus quiver and let out a shaky sigh. “bro… you know we both know we have mutual feelings now, right? you’re allowed to make sounds. it’s not weird.”

Papyrus closes his eyes and nods, tips his head back and relaxes. Sans goes at the soul with an increased fervor, pulling a moan from his brother. “S-sans, that feels amazing. Does it feel that good when I did this to you?”

“maybe. it feels great when you do it.” He digs in a little more with his thumbs, and Papyrus’ soul leaks orange, the color growing in a small field around the heart. “oh, bro. is it really that good? you’re _glowing._ ”

“Shut up, Sa-a-a-ans,” Papyrus tries, but the fact that his retort is punctuated by a long, breathy moan seems to nullify his point. “I didn’t realize how sensual this was when I was doing it to you. I’m sorry if I made things awkward.”

“nah, it’s fine. it was more relaxing than anything else. you’re just already turned on, so it feels more erotic than normal.”

“Ah,” he says, and Sans isn’t sure if Papyrus is acknowledging the statement or the pressure. The magic around his soul flares for a moment, then the field shrinks as a bright orange tongue lolls out of his mouth. Sans watches him pant for a moment, then conjures his own in blue and meets his brother in a kiss, his hands still working on the soul as best he can.

Papyrus groans into his mouth, breathy and distant. Sans takes the opportunity to run his tongue along the backside of Papyrus’ teeth, which earns him a shudder and another moan. “heh. you want to go further with this?” he asks, pulling back from his brother’s mouth.

The taller skeleton closes his eyes and takes a moment to think. “I actually think we might be moving a little too quickly for my tastes if we jump straight to that step. I’d be comfortable with self-stimulation separately, even in the same room, but I need a little more time to acclimate mentally to the idea that this is… something you want as much as I do.”

Sans nods. “of course. you can go first, if you want.” He draws back, his hands a little fuzzy from the magic around Papyrus’ soul. He brushes them off on the couch as he watches Papyrus blush and reach hesitantly for his waistband.

“Y-you’re sure this is something you want?” Papyrus asks as he looks down at himself. “You’re… not going playing a joke on me?”

Sans can’t help but laugh. “bro, if i was playing a prank, this would have gone way past my comfort zone a long time ago. i really do want to have this experience with you.”

“Alright.” He exposes his pelvis, then starts massaging his ilium with both hands. 

God, his brother is beautiful. Sans is shocked into speechlessness by the movements of his brother’s phalanges, the way his jaw goes a little slack and his tongue comes out, the saliva escaping out the corner of his mouth, his eyes half-lidded, his hips rocking ever so slightly on the couch. His brother’s movements are nothing like he’s ever seen before, and he almost regrets not asking to go at the same time. He keeps his hands off his own body for now and resolves to just take in Papyrus’ movements.

Nimble fingers run down between his legs, and he summons up a magical cock, longer but not quite so thick as Sans’ own and glowing the same bright orange as his soul. It’s beautiful, and it suits him. Sans desperately wants to wrap his tongue around it, but he settles instead for balling up his fists inside his sweater pockets.

Papyrus is impatient, certainly, and it’s easy to tell in the way he moves. There’s a note of desperation that Sans hasn’t noticed before, but becomes much clearer as he sees his brother trying to hold back as he touches the glowing appendage. His fingers are still slow, sure, but he’s shaking with need and won’t seem to be able to bear the agonizing pace much longer. So, Sans supposes, it’s a good thing that Papyrus is setting his own pace. 

Sans lets out a shaky sigh of his own as he watches his brother speed up, encircling his cock with his right hand. He’s not sure if Papyrus is moving his hand or his hips, but he doesn’t really care. The taller skeleton moans as his eyes close, his back relaxing into the couch as his hips continue to buck. He just keeps moving faster and faster, his left hand on the cushion next to him, grasping at the couch in hopes of stabilizing, but he can’t seem to grab on tightly enough.

“papyrus,” Sans murmurs in awe, and his brother bucks harder upon hearing his voice, “you’re so beautiful. even more than i imagined.”

Papyrus flushes, then opens his eyes to look at Sans and grin wider than his brother’s ever seen before in his life. “N-nyeh! Of course I am! This is the Great Papyrus you are talking about, after all!” He draws in a shuddering breath, then adds, “Tell me more, Sans! Paint me a picture with your wo-o-ords!”

Sans doesn’t feel supernaturally compelled to do as his brother asks, which he notes and files away in some part of his brain. He does, however, feel extraordinarily aroused by the concept, so he decides to go all-in. “oh, bro, you look… radiant. like the sun. your movements are so purposeful, and i can feel your need from the other side of the couch. your tongue is really turning me on, and your dick is begging to be sucked off, and—“

Papyrus cuts him off with a small cry that sounds like shock at first before Sans realizes his brother’s eyes are closed again, his head thrown back and his breathing heavy. “Ah-! Sans, oh my g-god!” he cries as he sprays the front of his own ribs with his cum. It drips between, coating his soul in even more orange goo.

Sans can’t help himself after that. He brings out his own cock and starts to get off, glancing over at his brother every once in a while just to watch the afterglow. He’s something like halfway there when his brother speaks.

“S-sans,” he says, and his voice is breaking and quieter than Sans is used to, “do you think that maybe next time we could… use some kind of penetration? This was… great, but I’m not used to feeling so empty when it happens.”

To the surprise of both skeletons, Sans’ world whites out instantly out of nowhere under a crashing orgasm. He’s lost to the world, unaware of anything but the immense pleasure coursing through his body, unable to push a single thought out of his skull. His movements are reflexive, bringing him to a longer and longer completion mounting higher than he thought possible.

Everything is peace, for a while. He doesn’t know how long it lasts.

When he finally comes back down into awareness, his brother looks shocked. His cum is still fresh, all over the floor. “oh,” he says. “i’m sorry, papyrus, i didn’t—“

“That was impressive!” Papyrus cuts him off. “Surely there must be a way for the Great Papyrus to reach climax as quickly as you!”

“heh.” Sans looks down at himself. He takes a conscious moment to stop fondling the air where his dick once was, then brushes himself off. “yeah, there probably is. orgasm on command is always something fun to mess with, hypothetically, but i don’t know if i could do it.”

“That’s alright, Sans,” Papyrus says, patting him on the shoulder. “If I can puzzle out the way to make it happen to you, I’ll be more than happy. You just sit there and rest for a bit. I’ll clean up.” He stands, heading to the kitchen to get the cleaning supplies.

Sans decides to lie down on the couch to try to recuperate, but as soon as he closes his eyes, he drifts off.

 

He doesn’t wake up again until the sun is streaming in through the blinds in his room, and he swears he can hear Mettaton downstairs.

“I’d be offended if what you were suggesting wasn’t so… devious. And clever! It’d be the perfect plot twist! From out of nowhere! Mettaton was the culprit all along, sowing seeds of misdirection throughout the Underground! But no, I’ve been far too busy with my show to even think about something like that, darling. Have you tried Alphys? She’s certainly the type.”

“She said she couldn’t perform magic that strong.”

Mettaton pauses. “And you believed her?”

Sans assumes this is the part where Papyrus looks away in shame, because he doesn’t respond.

“Darling, Alphys is made of secrets she’d love it if no one heard. And I’ve got a lot of them! So, if you’re looking for information about her, I am the go-to robot! Or, if you’re looking for other things…”

Before Sans can even truly process the intent of the statement, Papyrus replies, “Nyeh! Mettaton! I’m already in a… fairly serious situation right now. I’d feel terrible about being unfaithful to him.”

“Who is it?” Mettaton presses, and Sans hears him move around on the lower floor, then pause. “Oh my god. Is it Sans?”

Papyrus lets out a weak “N-nyeh,” and Sans knows they’re in trouble.

“Ohhhh yes! A tale of forbidden love! Socially questionable actions! And raunchy as all get-out, if I know anything about you! It’s a perfect story!”

“Mettaton, please stop.”

“Oh, come on, Pappy! Don’t you want to be a star?”

Papyrus goes quiet for a while. Then, just barely loud enough for Sans to hear, he says, “Not like this.”

“Well, that’s your funeral! I’ll keep it in mind in case you change yours. Well, call me up if you need anything, sweetheart!”

“Sure thing,” Papyrus says halfheartedly, then starts trudging up the stairs to Sans’ room. He knocks on the door twice, then calls inside. “Sans, I brought you back to your room after you fell asleep on the couch last night. I hope Mettaton didn’t wake you.”

“nah,” he lies, “i was awake anyway. are we going to try asking more people today?”

“Yes,” Papyrus responds. “Grillby is next.”

Sans wraps himself up tighter in his sweater, because for some reason, the thought makes him feel very cold. “ok.”

**Notes for the Chapter:**

> this chapter was going to have a lot more mettaton in it, but then i got carried away with the smut. i'm pretty sure you guys don't mind, though.


	7. it's raining somewhere else

With the change in schedules and occupations from the new Queen had come a new timetable at Grillby’s: around lunch and dinner, it grew very busy, but during the afternoon it was slow-paced and in the morning after breakfast it was almost silent. Grillby didn’t like closing down during these hours, since anyone could come in at any time, and it made his job much easier regarding keeping his establishment clean throughout the day.

There is no one but the bartender in the restaurant when Sans enters, followed closely by Papyrus, who both sit down at the bar. “Grillby,” Papyrus starts, “we have some… questions that we need to ask you.”

“It’s been a while,” Grillby says, looking at Sans. “I was starting to worry.”

Sans gives him a dismissive wave. “i’m ok. well, not really, but that’s why we’re here.”

“Oh?” he says, looking to Papyrus. “What’s going on?”

“Sans has been the victim of someone’s magic,” his brother says. Sans leans over on the counter and stretches his arms out in front of him. “It has been making him forget things and lose track of entire days. We suspect you might be close enough to him to… make this happen.”

“Oh,” Grillby says, and goes back to polishing the counter.

“So… Why, exactly, do you believe we shouldn’t suspect you?”

Grillby doesn’t respond. Sans isn’t exactly surprised. Papyrus, frustrated, stands up and starts pacing the room.

“Everyone else has given us reasonable… well, reasons to believe that they weren’t the suspect, though many of them have holes in their cases. If you don’t give us anything, I might have to assume it’s you, and then… I don’t know. We’d have to do something.”

Sans presses his face into the counter as Grillby continues to ignore Papyrus. This isn’t going to go anywhere. He half-listens to his brother ramble with increasing agitation in the background. “Sans,” Grillby asks, in the middle of one of Papyrus’ statements, “would you like some water? You look like you’re having a bad time.”

Sans wants to sit up and wave it off, but he is having a bad time. He wants to tell Grillby that he shouldn’t be interrupting Papyrus, that he should take him seriously, but he can’t get his mouth to form words. He feels sickly and dizzy. “mmh,” he grunts in response, so Grillby gets him something to drink. He sips at the glass, and it doesn’t help the feeling much. It just seems to make his head fuzzy and numb. But at least he’s not feeling sick anymore, he guesses.

When he finishes, it’s apparently much faster than Grillby had expected, as he remarks, “Empty already? You might want to slow down before you make yourself sick.”

Sans tenses as he feels his heavy head lose another memory, pressing his face back onto the counter and trying to grasp the wood so that he can have something to ground himself through his mounting arousal. Papyrus sits back down next to his brother and sighs, going silent and staring at the bartender. Maybe he’s out of things to say.

“Is this all you came in for?” Grillby asks, and Papyrus gives a sigh of exasperation.

“It’s not as if I could come in for much else,” he says. “I’m very preoccupied with my brother’s well-being, and I’m frustrated that you won’t answer any questions.”

Sans looks up to see Grillby’s reaction, almost falling off his seat when he sees the light hovering just behind the fire elemental’s shoulder. He tears his eyes away for a moment to look at his brother, who doesn’t seem to have noticed that it’s there, despite looking right at Grillby. Maybe he’s at a bad angle. Maybe Grillby’s natural light is making it so that Papyrus can’t see it. He doesn’t know. He doesn’t care after a few more moments trying to resist. He can’t keep his eyes away. Giving up is like slipping into a warm bath, and the comfort wraps itself around his bones. He crosses his arms on the counter, then rests his chin on top of them so he’s perfectly angled to look at it without having to keep his body upright.

Papyrus keeps talking, but his voice fades into the background as Sans continues to stare at the light. His brother sounds far away, like he’s underwater. But he’s not drowning, he’s not in any danger at all. He’s safe, and that safety is so peaceful that he nearly slips down out of his chair out of relaxation rather than surprise.

The light starts to move, and Sans makes sure he can see it all the while. It floats around his head, then makes its way across the floor. He slips out of his seat to follow. He might be able to hear Papyrus from far away, but he doesn’t know what he’s saying. It’s not important, anyway. He just has to follow the light, and everything will be fine. 

Sans follows the light all the way out the door.

Something is wrong, part of his mind says. Usually, when the light appears, it’s in dreams, or at the very least, he’s restrained. He’s not restrained now, nor is he dreaming, he thinks. Is this his own doing? The idea arouses him, but seems unlikely. The ability to focus on magic would conflict entirely with how good he feels right now and how little he’s thinking. Every thought takes so long to push out of his head that he’s halfway across Snowdin before he finishes the idea of him doing this to himself, like he’s half asleep. There has to be a place warm and safe for him to relax and take in the light, doesn’t there? Is it leading him there? Maybe if he just reaches out a little, he can—

The light moves away from his hand, and he has to walk faster to catch up with it. There is a soft protest in his chest that never escapes him. He simply moves forward in single-minded pursuit of the light, chasing it until it disappears into the snow blowing across the road out of the town. He considers going in after it, but its hold on his mind has already started to wane, so he instead collapses to his knees and stares at the ground.

What the hell _was_ that, he asks himself. Why did he actually get up and leave his brother at Grillby’s in the pursuit of some stupid light? Maybe Papyrus was right. Maybe it is more dangerous than he thought, if he can be feasibly led anywhere like the prey of an anglerfish.

It takes Sans a few moments to realize that Papyrus is kneeling next to him and looks very concerned. “Are you alright?” he asks.

“y-yeah,” Sans stammers. “i’m fine. i think.”

“Do you think you can walk?”

Sans tries to stand, but his legs don’t seem to be working properly, so he wobbles and falls into his brother. “guess not.”

Papyrus gives a small huff, more out of amusement than exasperation. He wraps his arms around Sans and lifts him up, heading back toward their house. “So, obviously Grillby is our top suspect at present, since I have no way of telling how much of this was withholding information and how much was just ignoring something that didn’t concern him. Alphys… I’ve been led to believe she might be more guilty than we first believed, but I don’t know whether or not we can take Mettaton’s word at face value. It’s just so frustrating! I…” Papyrus stops for a moment, then asks, “Sans, do you have sexual feelings for Grillby?”

“what? nah, i don’t think so. i wouldn’t say no if he asked, but—”

“Then why can I feel your soul straining like you’re aroused?” his brother presses as he unlocks the door. “You can’t hide it from me.”

Sans groans as Papyrus puts him down once they’re inside. “i don’t know. there’s just some word that i can’t figure out that people keep saying that makes me forget something, and then because of the light, when i forget things i get horny. it’s the same word that made me cum all over the floor last night.”

“And you don’t know what it is?”

“no. i feel like i might, but i think whoever’s doing it wants me to not know what it is. maybe so that i don’t overdo it and forget everything. you know. hitting the pleasure button too many times, or whatever.”

Papyrus puts him down and stares at Sans, his expression inscrutable. Then, “Do you want me to help you reach… climax… without the aid of that word, then?”

“god, yes,” Sans replies. “please. i want you to—i—i can’t believe i’m saying this—i want you to fuck me. i want you to do whatever you want to me. i want you to take control.”

“I’m a little worried about the effects this light has had on you,” Papyrus says.

“please,” his brother begs, “i’d rather it be you than anybody else. thinking of what to do on my own is so hard lately. i need you to give me direction.”

The taller skeleton stares intently at the nearest wall. “You’re certain.”

“yes.”

“Then I need you to go up to my room and take your clothes off. Prepare yourself, sit on the bed, and wait for me.”

Sans doesn’t waste any time bolting up the stairs as fast as his legs will carry him and almost slamming the door to Papyrus’ room behind him. He undresses in record time, discarding his clothes in the corner near the computer. Then he summons up his cock and sits on the bed, and a peace he’s only felt in the dreams descends on him. It would seem, then, that it’s making him both horny and submissive. Sans doesn’t have a problem with that. He’s never really been one for taking the reins in a sexual situation anyway.

It feels good to just sit there and breathe as he waits for his brother, enough so that he doesn’t really know how much time has passed when Papyrus enters. Though he appears serious on the surface, Sans can detect a hint of apprehension in his expression. He doubts that Papyrus has had any sexual experiences with another monster. “How are you feeling, Sans?”

“pretty good,” Sans replies. “relaxed, mostly. it’s nice to not have to concentrate on thinking about what i have to do next. so. what are we doing?”

“Experimenting,” Papyrus replies, reaching into his brother’s chest and pulling his soul down and out of his ribcage as he teases Sans’ head with a thumb. Sans moans, and the grin he gets in turn from Papyrus is devious and only serves to turn him on more. His mind grows hazy with lust, and part of him wants to make a move, but he reminds himself that doing so would completely defeat the purpose of letting Papyrus lead the way. His tongue manifests all on its own, and he reaches it out toward Papyrus, hoping it will signal that he needs more.

The taller skeleton seems to get the message, manifesting his own soul and allowing it to rub up against Sans’ in midair as he frees up his hand to pin Sans down by the wrists. “Wouldn’t want you taking things into your own hands, hm?” Papyrus’ words rush straight to Sans’ cock, and Papyrus chuckles as he makes light touches here and there on the sensitive magic. “You got harder when I said that.” Then he looks distressed for a moment. “How much further do you want me to go with this? I’m… not sure what to do yet, really.”

“just do what you’re comfortable with, bro. everything you do is great no matter what. you are the great papyrus, after all.” He stops for a moment, then says, “if i don’t like something you’re doing, i’ll let you know right away.”

“Okay.” Papyrus resumes the little touches on his cock, then makes a small hum as the souls rub together. “How good would you say you are at following directions?”

Part of him lurches forward in ecstasy at the thought, so he gives a breathless laugh. “probably pretty excellent, right now.”

“Heh. Okay, go pick up your sock.”

Sans should be surprised at how quickly his arms struggle in his brother’s grasp so that he can move himself downstairs, but he isn’t. He’s been through all this before, and even before the light, there was always some part of him that desperately wanted to be told what to do, and would come to the fore when in situations such as these. He’s just glad that now he gets to experience the feeling for someone that he loves. Papyrus keeps him pinned down as he makes small soothing noises, his expression wrought with concern.

“I was joking,” he says, his voice so soft that Sans feels he could lay his head down on it and fall asleep. “But that, um, answers some questions, I suppose. I didn’t realize how vulnerable you are like this. I’ll do my best to take good care of you.”

Sans gets even harder, and his soul swells as it continues to grind against his brother’s. “thanks.” The desire to get up ebbs away, which is good, considering the circumstances.

“Now then, uh, keep your arms right there where I’ve pinned them,” his brother orders. “Don’t move them unless I tell you to.” Sans nods, but he isn’t sure where his brother is going with this. He doesn’t even feel Papyrus’ hands leave his wrists. The sensation remains even while he can see the taller skeleton’s hand come back into view and start pressing the souls together manually with a bit more force, making further friction that goes straight to Sans’ head and makes it hard for him to think. He can sort of feel Papyrus’ emotions, if he tries, and it’s terribly intimate, but it’s too difficult to focus right now with his mind so clouded with lust.

“nnnngh… god, papyrussss…” he moans, bucking into his brother’s hand. For a moment, Papyrus starts to stroke him, but then he looks distressed again.

“Sans,” Papyrus says, pausing the friction on his cock, and Sans wants to plead him to keep going, that he needs this, but he can’t seem to find his voice. “Your eyes are doing something… strange.”

“whazzat, bro?” Sans slurs.

“They’re making little heart shapes instead of circles.”

“’s probably because i’m feeling so good,” he replies. “soooo good… p-please, keep going.” His soul drips as his tongue does, and he looks up at Papyrus with all the devotion he can muster. “you’re so good at it. i’ve never felt anything better than this.”

Whatever hesitance Papyrus had is gone after Sans speaks, his chest swelling as his smile grows. “Well, it’s only natural that I would be adept at all sorts of things, even if I have never done them before!” He manifests a cock for himself, the appendage glowing as much as Papyrus’ expression after the praise. Sans wants to wrap his mouth around it so badly, but he can’t sit up, so he wiggles his hips in an attempt to entice his brother into making friction in a more accessible area.

It seems to work well enough. Papyrus’ eyes are drawn to Sans’ pelvis, and like a magnet, his cock is drawn to it too. At first his thrusts are slow, experimental; he picks up speed when he realizes the magic giving Sans his own pleasure at the sensation doesn’t prevent him from moving quickly. Sans quakes with pleasure, his magic giving him the pleasant sensation of being filled up and the soul friction giving him even more to work with even as Papyrus seems to forget about Sans’ cock and instead holds onto his pelvis with both hands.

He tries to help, tries to grind himself more efficiently into Papyrus, but he’s never sure if it works. All he feels is his own overwhelming pleasure and peace. His soul sings a mantra up into his head: _please fuck me, i’m yours, don’t stop._ He doesn’t remember the last time he’s felt this good, not even with the light.

He wonders briefly if he could somehow get Papyrus to fuck him while he was looking at the light, and that only serves to make him even hornier, but the thought is gone in a second when his brother climaxes inside of him, shuddering and shaking throughout as he cries Sans’ name. Sans watches his expression shift in the throes of pleasure, grinds into him harder, and he can’t stop himself from grinning and drooling a little. God, his brother looks so good.

Papyrus withdraws his own soul once he comes down from the high, then goes back to stroking Sans’ cock and massaging his soul with the other hand. “I’m sorry I finished so quickly. I just got excited, with it being my first time and all, and…”

“don’t worry a-a-about it,” Sans replies. “just don’t stop. please, please don’t stop.”

Papyrus obliges, stimulating Sans with an increased fervor. “I want to make you feel as good as you did with me. Just focus on what you’re feeling. My words aren’t as important as the sensations.”

Everything seems to dim after he finishes speaking this time, the rest of the world fading slightly as he moves further inside to wrap himself up in the pleasure. It’s warm and feels better than anything he’s ever experienced in his life. His entire body is lit up with a primal need. He needs to finish. He needs to climax, and soon, or he fears he may explode with the pressure of so much pleasure built up inside him.

Sans is so blissed-out he almost doesn’t hear his brother speak. “Now, Sans, I’m about to press into your soul. When I do, you’re going to have a very powerful orgasm, understood?”

He can’t even formulate words anymore, so he nods, trying to focus on Papyrus’ face. He’s so beautiful. Radiant, even, like the sun. Sans can only reflect a small portion of Papyrus’ light in the smile he always wears that gradually widens as the sensation builds.

He tries to say “I love you,” but his tongue won’t work, so he instead looks up at Papyrus with as much love and adoration he can force into his expression. Papyrus seems to get the message, as he gives Sans a gentle smile in return.

Then Papyrus’ thumb presses down, and Sans is lost, adrift without an anchor in the sea of pleasure, crying out incoherently until he can no longer even think to do that. It’s so good. It’s all so good that he can’t even think of anything else. He hangs onto the one thing that comes to his mind without effort, his brother’s name, issuing it forth like a chant as though doing so will prolong his dizzy spiral of overwhelming bliss. It leaves him on every panting breath, drawn out by his contented moans.

It winds down slowly, and he uses his brother’s name to anchor him, to help bring him back to the present. Papyrus is holding him close, hugging him and running his fingers along his brother’s skull. “Are you alright?”

“yeah,” he breathes. “i’m doing great. thank you.”

**Notes for the Chapter:**

> sorry this took so long, life is getting harder to deal with while trying to write this thing. hopefully i'll have more motivation in the future.


	8. anticipation

Despite having inclinations toward Grillby, Papyrus decides to finish with all suspects before moving forward in his investigation. He asserts to Sans that only one remains, and the pair set out for Waterfall. Papyrus murmurs under his breath constantly as they walk, and when they come to the room with the crystal cheese, Sans sees why. The seam between this room and the next, the one with his telescope, stretches out much longer than it ever has before. In the center on the north wall sits a grey door. Papyrus strides up to it, knocks three times, then waits.

[* Come in,] says an all-too-familiar presence in the back of Sans’ head. He doesn’t hear it so much as he feels the soft static and knows instinctively what’s being said. Papyrus seems to be experiencing the same phenomenon, as he opens the door and beckons for Sans to follow.

The room on the other side is featureless and grey, and in the center sits a figure Sans has only seen in his mind and projections of his thoughts.

“gaster?” Sans asks, and the figure smiles, holding up a single hand. “papyrus, how did you find him? i’ve been trying to do this for… a really long time.”

“It’s a temporary measure,” Papyrus says. “He’s not solid, and he can’t manifest like this for long periods of time. And he can only do it here, in this other world, and I can’t always access it. But I thought it might help your mood some to see that he is still… around.”

“yeah,” Sans replies through his building tears, “yeah, it has. thank you.”

“So, naturally, I thought I should ask him if he’s done anything to you,” Papyrus adds. “After all, he certainly could mess with your head if he wanted to, and probably would if he felt he was helping you. So.” He turns to Gaster. “Do you have anything to say for yourself?”

[* You know I have no ability to change things that much,] Gaster says in the same static as before. [* I could never cast lights from my current position.]

“But they have only appeared in Sans’ dreams! And we all know that you can influence dreams.”

[* They appear outside his dreams,] Gaster says, and Sans nods as confirmation.

“yeah, uh, that’s… actually why i left grillby’s. i was following the light.”

Papyrus sighs. “Well, that’s… something. I wish you had told me.”

“didn’t really come up,” Sans says, wiping his face dry. Gaster moves over and pats him gently on the shoulder.

[* I’m happy to see you again, Sans, but I fear this venture is misguided. Papyrus, you and I both know that you already know who is perpetuating this.]

Papyrus sighs and rubs the heels of his palms into his eyesockets. “I told you that I had some suspicions, Gaster. I do not actually know who is doing all of this.”

[* You know it is not me. And whether or not you will acknowledge it, you do know the culprit.]

In a huff, Papyrus stands. “Sans, I’ll be outside when you’re ready. I need to think.” He walks out the door and closes it behind him.

“so uh… who is it?” Sans asks.

[* Hahaha… I am sorry. Telling you the answer would result in a timeline that I am certain you do not want to experience. As it stands, this will not be at all enjoyable for you, but things would only be worsened if I were to reveal who is behind all this.]

“things are going to get worse?” he asks, curling up a little. “you’ve gotta be kidding me.”

[* Things will get worse before they get better. But they will look up eventually. Remember that.]

“ok, i guess.” He sighs. “so… how have things been for you?”

[* The same as they always have been, and the same as they always will be. But I am enjoying this moment that we can share together, even if I am not experiencing it in the same linear fashion as you would.]

“heh. yeah, i guess the core kind of does that to you. i’ve been ok. it’s… kind of difficult lately. hey, actually, i didn’t know that papyrus knew about you. i thought he… you know… forgot about you with the rest of everybody else except me and alphys.”

[* He did forget about me,] Gaster responds. [* But he met me again at a later point, and we have had some discussions.]

“interesting. i just figured he would’ve told me, since you told him i remembered you, i guess, and our contact has been so sporadic.”

Gaster shrugs. [* I have no control over what he does and does not tell you.]

“i mean… you could have convinced him.”

[* It would not have been the right thing to do.]

Sans looks at the ground and chuckles. “yeah, i guess. and it led to this, so i don’t mind too much. i’ve just… missed you.”

[* I feel the same way.]

“do you know if you’ll ever be able to… you know… come back?” He wrings his hands, and Gaster puts his hand on Sans’ shoulder.

[* There is a point at which I can no longer see anything, so I must assume so. But it is not in this timeline.]

“ok.” He stands, throwing his arms around the former Royal Scientist’s midsection. “pap’s probably getting antsy out there. i want to talk again soon, though.”

[* Of course. I’ll do my best to keep in touch.]

“thanks. welp, see ya,” Sans replies, waving at Gaster and exiting the room. Papyrus is waiting down the hall, and Sans traverses it in what feels like an instant. When he looks back, the hallway with the door is gone. “so… he’s not coming back this timeline,” Sans says. “but he will be back at some point.”

“Well, that’s something,” Papyrus says, staring at the cheese.

“hey, uh, are you ok, bro?”

“I have no idea who he’s referring to. I have one last idea, but I know an interrogation of that person would be useless because there is no chance of a useful response. I just want you to be safe and happy and I can’t seem to do that,” the taller skeleton says. “It frustrates me that I’m so powerless to make you feel better.”

“you did pretty well last night,” Sans remarks, and Papyrus’ cheekbones grow a few shades darker. “hey, wait, shouldn’t you be… you know… doing royal guard stuff?”

“I’ve been pardoned from my duties by Undyne in order to help you,” he replies hastily. “The same for you, but to get well instead. Can we go home? Please?”

Sans chuckles. “wow, sounds like you really want to jump my _bones_.”

“Augh!”

“anyway, you’re the one in charge, remember? take the lead.”

“I didn’t realize that was… something you intended to persist,” Papyrus says, staring at the ground. “But I suppose, if you insist, I will continue.” He takes a moment to collect himself, then an intensity sets into his expression as he steps forward with confidence. “Follow.” His voice is firm, yet affectionate, so Sans obeys.

It’s always felt natural for him to follow his brother rather than lead, but now moreso than ever. He doesn’t have to put any thought into trailing slightly behind his brother to wherever it is they’re going. His legs seem to move all on their own. He thinks his perpetual grin might be a little larger than usual. It certainly feels that way. He also feels marginally sleepier than usual, though he thinks that may be the light’s influence on how he’s grown to view submission.

They walk for what Sans thinks might be a really long time, but he’s not sure. Whatever the case is, he doesn’t mind. It’s a comfortable pastime. They do finally stop in front of their house, and Papyrus turns to his brother. “Are you feeling alright?”

Sans nods. “yeah. i feel pretty good. sleepy, though.”

“Do you want to take a nap before we get started?”

“yeah, probably.” Papyrus opens the door and steps inside, allowing his brother in before shutting the door. “i’ll just take the couch.”

“Alright. I’ll be in my room when you’re ready.” Sans climbs onto the couch and puts his head down on the armrest as he watches his brother walk up the stairs. When Papyrus closes his door, Sans lets his eyes close.

He must have been exhausted, because he doesn’t remember lying there trying to fall asleep at all. The next thing he knows is that he’s restrained, like he always is right before the light shows up, but it’s not there yet. He can still think clearly, which is new and strange. He doesn’t think he likes it. He struggles, and for once, he actually manages to break free.

The world around him is dark, so he can do nothing but feel around with his hands and hope that he can figure out where he’s going. He’s next to a wall, that much he can discern. He feels his way to the corner, then along the next wall where he finds a door. It’s not locked, so he tries opening it.

On the other side of the door is his own living room. He looks back at the room he’s in, now illuminated by the low light coming through the doorway. The wedge of things he can see includes his brother’s bed, along with his brother, sleeping soundly on top of the covers. It doesn’t look like he meant to fall asleep, but then why would the light be off? Was there foul play involved? Did someone put his brother to sleep the same way that they control him normally? Was there an interruption? Is he even awake right now?

He decides that regardless of the situation, he doesn’t want to be awake right now, and closes the door, hopping up on his brother’s bed and curling up next to him. This has the safety he desires most from the dreams, as well as the implication of real rest. He closes his eyes again, though nothing seems to change as it’s completely dark both ways. Papyrus lets out a soft breath, and Sans snuggles up closer to him, letting himself drift off.

 

“Sans? Sans!”

Sans groggily opens one eye. Papyrus is shaking him and seems somewhat alarmed. “yeah, bro? what’s going on?”

“When did you _get_ here? I don’t recall falling asleep, yet somehow I found myself waking up with you in my bed!”

“is that a bad thing?” Sans asks, trying to wake himself up. The room is still dark, so it’s easier to adjust to waking than it might otherwise be.

“Well, no, but… I just… I’m a bit alarmed.”

“what’s the last thing you remember?”

Papyrus sighs, and the sheets rustle as he curls up into himself. “Reading, I think. But my book is bookmarked properly and sitting by my bed.”

“do you remember seeing anything before your memory cuts out?”

“No,” he says, his voice quivering. “The last thing I thought was that maybe I should take a nap because I was starting to feel exhausted, and then I was waking up totally refreshed.”

“maybe somebody heard you,” Sans offers. “i don’t know. i don’t even know how i got in here. it was like the start of the other dreams, but the light never showed up, so i could break out. but i was still tired and wasn’t sure if i was dreaming, so i decided to finish my nap with you.”

“Hm.” Papyrus sighs. “You said that these things could happen outside of dreams.”

“yeah?”

“What if they never were dreams in the first place?”

A cold feeling rushes through Sans’ body. It seems unlikely, but… if he was being woken up in between his naps each time, it would be possible, he thinks. “…maybe. it could happen, i guess. i’d rather not think about it right now. do you still want to…?” He trails off.

“Um… soon, yes, but not quite right now. I’m still… not feeling well.” He’s shaking a little, so Sans curls up next to him and holds him. “If you want to do little things, I’d be alright with that.”

“hey, bro, you’re gonna be ok. i’m here for you if you need me.”

Papyrus pulls his brother closer to him, nodding into his shoulder. Sans gives him a small squeeze and reaches up into Papyrus’ ribcage, rubbing his thumb into his brother’s soul. Papyrus sighs and leans back, and in the slight glow that his stimulated soul provides Sans can see that Papyrus’ eyes are half-closed already. He stays at his brother’s side, digging his thumb in a little deeper to try to relieve the tension. Then an idea occurs to him. He pulls the soul out of its housing and manifests himself a tongue.

“Oh,” Papyrus says.

“is this ok?” Sans asks, bringing the soul closer to his face. Papyrus nods, so he licks a long stripe up the middle of the inverted heart. Papyrus shudders and lets out a long, content sigh. “sounds like it felt pretty good.”

“Y-yes,” Papyrus replies, and it looks like he’s relaxing quite a bit. “Keep going.”

Whatever parts of Sans are still lethargic from sleep surge forward with energy at the command. He can’t stop himself from grinning. “if you insist,” he says, then presses the soul up against his tongue. Papyrus moans softly, letting himself sink further into the bed. Sans curls his tongue around the edge, waiting for a reaction, but it appears that everything he’s doing is only serving to help calm his brother down. That’s fine, though. He doesn’t mind having to wait a while for sex as long as it means Papyrus is comfortable.

As Sans runs his tongue over the edges of the soul in his hand, he notices his brother’s eyes closing, and he massages circles into the now-wet surface to facilitate his brother’s further relaxation. Papyrus exhales, and as he does, his eyes slide shut. Sans keeps massaging Papyrus’ soul for a little while, then puts it back in his brother’s chest where it belongs and resumes a full hug. His brother’s arms have long-since relaxed at his sides, but he smiles a little at the contact.

“just let me know when you’re ready, bro.”

“Of course,” Papyrus says, and he sounds like he’s miles away on the inside.

Sans puts his head on Papyrus’ shoulder and waits. But he doesn’t mind waiting. He could do this for the rest of forever and be content.

If the look on Papyrus’ face is anything to go by, they both can.


	9. don't give up

Papyrus takes a little while coming back to the world of the awake and aware, so Sans takes the opportunity to go get himself a glass of water. He downs the whole thing in one go, then absentmindedly places the glass in the fridge, climbs the stairs again even as he wobbles slightly on his suddenly uncertain legs.

When he opens the door, Papyrus has turned on the light and is frantically rubbing at his pelvis, already having completely stripped himself of all clothing. “Oh, good. You’re back,” he says. “Sorry, I just…”

“you don’t need to apologize,” Sans replies, pulling himself up onto the bed next to his brother. “it’s ok. i’m glad you’re getting yourself ready.” He takes off his sweater and shirt, then his shorts. “anything in particular that you want me to do?”

“Take over for me. I’d like to be able to focus on the sensations.”

“ok.” Sans reaches forward and starts putting pressure on his brother’s ilium, rubbing slow circles into the surface of the bone. “just relax, bro. you can lie back and just tell me what to do and everything will be fine.”

Papyrus doesn’t say anything for a few seconds, closing his eyes and lifting his hips into his brother’s touch. “Fill me up,” he says, and it sounds more like a plea than a command, but Sans will take what he can get. And he’d be lying if he said it wasn’t attractive to hear, besides.

The smaller skeleton deliberates for a moment or two on what method he wants to use to help Papyrus, but it doesn’t take him long to make a decision. He conjures a thick tendril in bright blue, then slides it into his brother’s pelvis. Papyrus lets out a long moan as the blue works its way through him, feeling its way up his spine as far as it’ll go. It sticks at the base, just wide enough to fill him completely, and rubs the undersides of his ribs. A tongue materializes between his teeth, then his jaw parts and it falls further down on his chin. Sans runs his thumb along his brother’s jawline. “god, you’re beautiful.”

Papyrus squirms, his eyes barely focused on Sans. “T-thank you,” he says, flushing with magic as he does. Sans can tell how tense Papyrus’ soul becomes at the remark, so he uses the tendril to reach up and encircle his brother’s glowing heart. A full-body shiver runs all the way through Papyrus, and he moans again when the surfaces rub together. “I also find you, n-nyeh, attractive.”

“oh. i mean, i hoped so, but thanks.” He reaches up to run his fingers over the outside of Papyrus’ ribs. He starts to feel a strain in himself as well, so he conjures himself a cock. It’s already hard, but he doesn’t want to focus on himself right now. Doesn’t quite feel right with Papyrus still unfinished. So he lets go of the soul with the tendril to curl around his brother’s spine, then slides up and down at a leisurely, sensual pace. 

Papyrus shudders and runs his tongue over his teeth. “S-speed up, Sans. I can’t—“

At the command, the tendril seems to move all on its own, picking up the pace without missing a beat. Sans’ arousal lurches in his gut at the automatic response.

His brother looks at him, erratic blinking marking his features. “I want you to finish first,” he says. “It’s easier for me when I can watch you, anyway.”

“ok,” Sans replies. “how do you want me to—“

He can’t quite finish that thought, since Papyrus has already wrapped his hand around Sans’ cock and started to give his own friction. “Focus on this,” he says, his voice firm in spite of everything. “Focus on my hand on you, on the movements and pressure.” His skull feels full of cotton, but everything washes away when Papyrus quickens the pace and Sans ejaculates much sooner than he was expecting, He collapses onto Papyrus’ chest, nuzzling up against his brother and allowing the tendril to finish its job, which it does in record time, faster than it’s ever managed for Sans. Though, he supposes, it’s probably because his brother is still pretty inexperienced and hasn’t had a lot of time to build up a tolerance to sexual interactions.

“how was it?” he asks, noting that his brother never even had to conjure up any genitalia.

Papyrus pants as the tendril dissipates. “S-sans, that was… amazing. I felt so full, so complete… My only complaint is that now I feel empty without it in me.”

He shudders, feels himself lose something, something he can’t quite place, and then suddenly an orgasm is crashing down on his mind, tearing him under when he wasn’t even half hard again yet. Immobilized by pleasure, he rides it out, lets himself sink into the darkness for lack of a better course of action, letting his body quake under the gravity of the indulgent assault.

He drifts, feeling the sensation flow through him, and after what feels like an eternity it lets him down gently back into the realm of the aware. He looks at the bed in front of him, Papyrus looking a little concerned, the sheets now covered with a fresh layer of his ejaculate. But something isn’t quite right. He gets a little closer, examines it. It’s a little pearly, more luminescent than he’s used to. Fuller, maybe. What’s different? What would have changed things? He reaches down, dips a finger in it and gives it an experimental taste, just to see.

The cum tastes like a high-pitched laugh and vines wrapping around his arms, and he realizes as it comes back to him that he’d lost the memory through orgasm. To a degree, he literally came his brain out.

The thought of that alone is enough to send him over the edge again, shuddering and doing his best to keep himself from falling into the rapidly growing pool of luminescent cum, mixing orange and blue on the edges where Papyrus sits. He feels like he could keep doing this forever, like his ectoplasmic penis will keep going until the end of time without even so much as being touched. All he had to do was hear the word—he still can’t figure out what word it was—and he was gone, so far gone he can hardly even make sense of it now.

When he comes back down from the high, he doesn’t realize what he’s forgotten, but he does know that he doesn’t have whatever it was he regained from tasting the cum before, and that gives him peace.

“Sans, I need to wash this,” Papyrus says, now standing at the edge of the bed. “It’s not directly your fault, but I did realize it after you came the second time. You… had a lot in you.”

“…thanks?” he says, uncertain. “hey, can i ask you something?” 

“Yes?”

Sans wrings his hands a little. “what happened… you know… before all of this started? but after frisk left? i feel like it was something important, but…”

Papyrus’ eyes go wide. “You… don’t remember?”

“i don’t remember a lot of things.”

“Oh, no. Oh, no, no, no, no,” Papyrus says. “I need to, I, I need to f-finish this first. W-wait here.” His voice is stuttering and uncertain, but Sans obeys anyway. Papyrus bolts out the door with both their clothes and the sheets toward the laundry area, and Sans is left sitting naked on a sheet-less bed. A cursory glance around the room shows that Papyrus has moved the book he was reading to somewhere that isn’t the bedside, so he can’t take a peek at it now.

When his brother returns, he sits on the bed next to Sans, his back rigid and his fists clenched. “so… what’s up?”

“You said that you only forgot painful memories from other timelines.”

“do you remember the situation?”

Papyrus sighs. “Yes. We had quite a few moments I held quite close to me. It was… a time before I admitted my feelings for you, but there were also parts where I didn’t feel awkward being around you in an intimate context. It was… calm. Which I don’t usually like in situations! But it was nice. So I… don’t understand why you would have forgotten unless something has gone wrong and you’ve started to lose other memories. Ones that you might have preferred to keep.”

“it’s possible that i forgot on my own.”

“No, it’s not.” Papyrus shakes his head. “The one I’m thinking of in particular was fairly recent, and you exhibited strong positive emotion about it. With how rare those events are, I doubt you would have forgotten.”

“do you think maybe they want me to forget everything good except the dreams? so that i don’t know anything else, and i’m more vulnerable.”

“No,” his brother says, a little too quickly. “No. There’s no way.”

“how do you know?” Sans asks.

“I… I need to talk to Undyne,” he replies. “She’ll know what to do.”

“that’s not an answer.”

“I know. I just… want to wait a little to explain so I don’t have to do it twice.”

“ok.” Sans doesn’t bother arguing. He tips backward slowly until he’s lying on the bed, stretching his arms out. “bro, you realize you called undyne over and put our clothes in the wash but we’re both… you know. not wearing any clothes.”

Papyrus blushes. “I… had forgotten about that, actually. You should put something on while I call her and prepare my room.”

Sans nods, making his way to his room. He goes through his drawers extensively and finds a new pair of shorts and a shirt along with a pair of socks. He’ll have to just stay inside until the sweater is done in the wash, he guesses. Not that it should be an issue.

When he’s finished, Papyrus has already gotten re-dressed in one of his more casual outfits—not the entire “Cool Dude” getup, thankfully—and has remade his bed with fresh sheets. “There. Undyne will be none the wiser. I think.”

There’s a knock on the door, but since the door is unlocked it’s mere seconds before Undyne comes barging in anyway. “Alright, what’s going on?” she asks, closing the front door behind her. Her breathing is ragged, and Sans fees a pang of worry.

“Did you just run here from Waterfall?” Papyrus asks, and she nods as she ascends the stairs. Sans feels lightheaded, so he leans back on the wall. He’s been feeling this way a lot lately, and he has to wonder if there’s something wrong with him. Maybe he’s getting sick, or he’s not staying hydrated enough. Maybe he should get some more water? Later, maybe. This is important. He tries to refocus on the conversation, and he doesn’t think he’s missed anything, since Undyne is still trying to catch her breath.

“Seriously, though, what’s up?” she asks after what seems like an age.

Papyrus takes a moment to collect himself, then says, “I know who’s doing this. And something more has started to happen, and there’s nothing I can do about it.”

Undyne looks at Papyrus with a very serious glint in her eye, then at Sans. “I think we may need to have this discussion… privately.”

“woah, woah, wait—“

Before Sans can finish, Undyne has already picked him up and set him outside Papyrus’ door. “Sorry, but I have some questions I need to ask first. Without you in the vicinity.” She shuts the door on him, and he stares at it for what feels like forever. He’s being shut out of a discussion about him, and something about that feels… wrong.

But considering he doesn’t exactly view the memory loss as a bad thing even now, it’s probably for the best, he reasons. So he turns.

The light sits inches from his face, closer than ever before, and he falls.


	10. respite

The light pulls him out the door.

He feels free, in a way. Clear of all thoughts and their consequences. Nothing left to trouble him, nothing left to weigh him down. He leaves the house, following the light.

It no longer pulsates. Its shine is ever-present, never dimming. Sans fears he might have lost sight of it otherwise, or he would have, if he had the cognitive function to fear anything.

He makes it almost all the way to Grillby’s before he nearly trips over something. He breaks contact with the light for a moment—it stops with him—and notices the flower at his feet.

“Have you figured it out yet?” the flower asks. “Haha, who am I kidding? Your head’s completely empty right now.”

Something clicks in Sans’ mind, something else locks itself away. He falls to his knees and shudders as he subconsciously fights back a public orgasm. He looks briefly at Flowey, then gets back to his feet and looks back to the light.

He should probably be cold, something in his mind tells him. He’s not protected at all from the chill, but the light makes him feel warm, so it hardly matters.

“Hey.” The flower is talking again. “Where are you going? The water’s that way.” He points with a leaf, which Sans is able to note out of the corner of his eye. He feels dizzier than usual. “Go take a drink. It’ll be like the Lethe.”

Sans moves. The light goes toward the river, too, so he can start to follow it again. It leads him straight onto the boat of the river person.

“Hello, hello,” the river person says. “How are you doing?”

Sans can’t even manage dredging up a single word from the blank slate of his mind, let alone an entire statement about his person, so he instead lets out a sigh of contentment.

“Good, good, good. Everyone will be so happy to see you.” The river person pauses, then procures a glass from their person somewhere and dips it into the water. “You should have a drink. The water will make you forget.”

Sans takes the glass and gulps it down greedily, and when he finishes, the inside of his skull feels cool and wet and clean, juxtaposed with the inside of his shorts, which feel hot and wet and sticky all of a sudden. He’s too dazed to know what’s just happened.

“Good, good, good. Time for us to go. Someone will be very happy to see you. Keep looking at the light. Tra la la.”

That’s the easiest command Sans has heard in a long time. He fixates on the light in front of him, breathing deeply and letting himself sink further into its warmth. The boat starts to move, but that doesn’t matter to him. Nothing matters. He’s not sure how time is passing, only that the light is in front of him and that’s all that matters.

The voice of the river person, for a moment, penetrates his relaxation. “Tra la la. Who is doing this? The answer is right in front of you.” He doesn’t know what that’s supposed to mean. He might not even remember it by the time it’s relevant. He doesn’t care. If he forgets it, all the better.

The boat stops. The light starts to move again. So does Sans. The light leads him up to a door in a place that feels kind of warm. He wobbles on his feet. A voice comes from a speaker somewhere.

“Sans? Are you okay?” Alphys.

Sans doesn’t answer. He follows the light with his eyes. The light goes inside the lab, and he stares at the doors, whining softly.

“Oh, is it _that?_ Wow, this is… really something.” Flustered, probably aroused. Sans wouldn’t blame her even if he were capable. He is too. “Heh… heheheh. Do you suppose your master would mind if I played with you a little, as long as I made sure you got home safely?”

He shudders at the word “master.” It’s not a trigger, but the concept turns him on immensely. Will Papyrus want to share? He whines again, harder this time.

“I guess I’ll take that as a no. Come on in.” The doors open, and Sans can see the light again, so he follows it inside.

The lab is dark, which is fine, because it means he can focus on the light better. Eventually, it stops. A pair of unsteady hands move him onto a chair. His arms are bound, then his legs. The bindings are gentle, yet firm. Just like his brother. He blinks, even though the light doesn’t.

He blinks again, slower this time. His skull hums with the sweet emptiness he longs for.

“Sans? How are you doing?” Alphys asks.

“good,” Sans replies, soft and breathless. “the best i’ve ever been.”

“A-are you turned on?”

“i could cum right now,” Sans says, and it’s barely an exaggeration.

“Oh, I know,” she says. “I could too.” A giggle. “Do you want to?”

“absolutely,” he says, knowing that forgetting will make him cum and cumming will make him forget and the two are so inextricably intertwined that he can’t sort them out from one another anymore. Then, he adds, groggily, “in the name of progress.”

“Of course.” A hand brushes against his cock—painfully stiff, now that he realizes it’s there—through his shorts, and his entire body shivers at the contact. A few quick pumps through the fabric, and he’s panting and crying out, staring into the light and moaning and everything is going away so cleanly that he couldn’t imagine it happening any other way.

As he pants, he half-hears someone else panting, the sound of something wet, and he manages to push out a single thought: Alphys is getting off to this.

He doesn’t care, of course, can’t formulate an opinion of it before the light wipes the thought away again, but it’s impossible to completely ignore the furious masturbation happening in the background.

“Sans,” she pants, “empty.”

He doesn’t even know how much he forgets, just knows that it happens and the ensuing rush is enough to push him over the edge again, and within moments of his own moaning beginning, his voice is joined by another.

His master certainly won’t mind that another is using him for her sexual gratification just this once. It will be fine.

After a while, Alphys unties him. “Thanks, Sans.”

“of course,” he says.

“I’ve called your brother to come pick you up. I don’t want to risk you falling to the river person again. That was… unexpected.”

“ok.”

He waits. And waits. And waits. Alphys hands him another glass of water. He feels so dizzy and good and complete. His head feels thick and warm, like it’s filled with his own cum, but at the same time empty and moist, like it’s been washed out with the waters of the Lethe itself.

Sans hears the door open. The light is gone, and he’s not sure how long it’s been missing. He feels so sleepy.

“Sans?” Papyrus asks. “How are you feeling?”

Sans lets out a low moan and turns toward Papyrus. His younger brother is here, ready to take him up in his arms and keep him happy. He tries to grin, but he feels too dazed to make expressions.

“Oh my fucking god,” Undyne says. “He’s really out of it, isn’t he?”

“More than I’ve ever seen before.” He looks at Alphys. “Did you play around with my brother?”

“A little bit,” Alphys admits. “Do you think he minds?”

“Of course not. But that’s less important.”

“Do you know his… the person doing this to him? Do you think they mind?”

Papyrus sighs, then shakes his head. “No. As long as you both had a good time, they’ll be fine with it. Enthusiastic, even.”

She brightens up. “Oh. Awesome.”

“But that was also less important. What is important is that Sans wandered all the way to Hotland and ended up with you in the first place. We don’t know why that happened.”

“Cut the crap, Papyrus,” Undyne says. “You’re not protecting Sans with this. He can’t even hear you right now. We know exactly what happened, and I expect you to fill him in on why this is going on within the next 24 hours, since he wandered off when you were planning to tell him.”

Sans still has no idea what’s happening and barely processes each sentence as they enter his head before they’re wiped away again, so the conversation makes no sense to him. He chooses instead to whine quietly at Papyrus, unable to form words like “I want to have sex” or “I need to get off” or anything at all. Papyrus seems to understand nonetheless.

“Do you want to go home?” he asks Sans, and Sans nods eagerly. Papyrus picks his brother up. “You’re… sticky. I’ll need to wash your shorts again when we get home.” Then, he seems to recognize Sans’ still-hard member, and adds, “But after we’ve taken care of you.”

As they leave, Sans manages to pick up, “You know, Alphy, I wouldn’t mind if you wanted to try something like that. With me.”

Alphys shrieks. “W-which way do you mean?”

The door closes before Sans hears the answer, and his mind is so muddied that he wouldn’t have retained the answer anyway. His brother’s shoulder is comfortable and warm, and the rhythm of his footsteps lulls Sans into a dreamless sleep.

He opens his eyes on the couch.

There’s a note on the front of his shirt—he’s still not wearing his sweater—and it’s from Papyrus.

_Sans._

_You were asleep when we returned, so I decided against helping you get off. I did change your shorts, though. If you’re still aroused when you read this, I’ll be in my room. If not, you can do whatever you would normally do. I’m still trying to figure out how to break the news to you about who’s doing this, so I’m sorry if I seem distant._

_Everything will be clear soon._

_Papyrus._

An intriguing note, certainly, and Sans doesn’t want to have to wait that long to find out who’s been doing this. In part, this is because he wants to thank them, on some level, but on another, then he can finally ask all the questions he’s been storing up over this time period, like why they’re doing it, and why it feels so good.

He goes up to his brother’s room, his member still rock solid, and lets out a whining noise. He’s capable of forming words now, but it’s easier for him to simply make noise and wait for that noise to make its way straight to Papyrus’ sex drive.

He’s not too far off the mark, as only a minute later at most, Papyrus opens the door. “Yes, Sans? Did you need something?”

“i want you to touch me,” he says. “i’m all bothered and i want you to do something about it.”

“What do you want me to do?”

“anything you want. i guess if you have to have some kind of guideline, whatever you think i’ll enjoy the most.”

“Ah.” Papyrus takes a deep breath. “Close your eyes.”

Sans does, humming with satisfaction. Papyrus sits him down somewhere, moves his arms behind his back—oh, he’s being restrained, and now there’s an actual blindfold—huh. This wasn’t quite what he was expecting. He can’t move off of the chair, and he’s a little disoriented, but that’s okay. Papyrus will take care of him.

His shorts slide to the floor, guided by his brother’s hands. He lets out a bone-deep sigh, content through and through. This is what he’s wanted for so long, and finally he gets to receive it on a regular basis.

Shame that it had to come with the loss of many of his memories, he guesses, but he prefers that to the alternative of having to remember all those timelines.

He opens his eyes and sees nothing.

“Are you ready?”


	11. confession

“How are you feeling?”

Sans’ body sags in his chair. They’ve been going for a while, and Papyrus still hasn’t even tried to get off once. Sans finds this interesting, considering the highly dominant tone his brother has adopted for this interaction. “g-good. uh. tired.”

“Do you want to rest?”

“yeah, probably.”

“Alright. You’ve earned it.” Sans’ soul lifts at the praise. “One last go, or no?”

“yeah, actually,” he says. “i think i can handle one more.”

“Are you still receptive?” he asks, tapping the side of Sans’ skull. This is his way of asking if Sans is still capable of following commands that he might not be able to otherwise. Sans nods slowly. “Excellent.”

There’s a shuffling of clothing—sounds like Papyrus is finally taking off some of his clothes—and then he feels Papyrus lean over the back of the chair, close to his head.

“I’m going to summon up my cock,” he says, and god, it sounds so _weird_ when his brother says it, but it’s arousing all the same. “And you’re going to gratify me with your mouth.”

Fucking finally, Sans thinks. “ok.”

“Doing this will make you feel like I’m touching you. You’re allowed to finish before I do, but you will not stop until I have finished.”

“ok.”

“The process will make you feel more and more sleepy as time goes on. When I finish, you will drop into a deep, restful sleep.”

“ok.” A beat, then, “are you going to finish in my mouth?”

“Do you have a preference?”

He does—he wants to taste his brother, wants to take him in, but he doesn’t want to risk making him uncomfortable, so he says, “nah, not really. just do whatever.”

Papyrus considers this for a moment, then says, “In that case, my, ah, m-my cum…” It’s adorable how awkward he is about the terminology, and it’s a reminder of how innocent he is even as he’s taking on a highly dominant role. He takes a moment, probably to steel his nerves, then continues. “My cum will act as a potent soporific. You will swallow or spit as your preference dictates, but regardless, it will do its job and you will fall asleep not long after.”

God, that’s something else. “this is why you’re the one in charge, papyrus. that’s… really creative. thank you.”

He hums with approval, hugging Sans around the shoulders. “Thank you.” Then he lets go, circles around, and Sans feels the cock bump up gently against his teeth. They part, almost automatically but not unwillingly, and he slides his tongue across the head, an experiment in sensitivity.

Papyrus moans, bucks a little into Sans’ mouth, and not only does the sound arouse the restrained skeleton, but the commands seem to be working full-force, as he feels a pleasurable pressure around his own cock, like there’s a hand around it, slowly moving up and down at the same pace he moves his tongue. He lifts his hips as much as he can, but to no avail. The hand isn’t real. Both of Papyrus’ hands are somewhere else right now. Nothing to do but suck, then. Oh darn, Sans thinks, sarcasm evident in his stream of consciousness. 

Well, better get to it, then.

He runs his tongue along the underside. It’s a little more difficult than he would like to give friction, since he doesn’t have cheeks in the traditional sense, but he makes do with just the tongue and light grazing of the teeth. His tongue laps up the sides of Papyrus’ cock, and he’s transfixed, even though he can’t see it. It feels so good in his mouth, even without the immediate rewards. He’s surprised that he even knew how to last so long without ever having experienced this. He’s pleasantly drowsy and feeling good.

“Ah, Sans,” Papyrus says, yes, suck until I’m empty—“

And then nothing else matters.

Sans chokes for a moment, feels the intertwining of forgetting and orgasm even as his brother’s cock still rests on his tongue, and everything fades out for a moment. He’s so tired, but it feels so good. Papyrus’ member twitches on his tongue. He can’t think, can’t formulate any ideas now. His head fills up with cotton, and then he’s moving much faster, desperately trying to finish his brother, no longer savoring things because he no longer has the capacity to process what “savoring” even means.

It’s impossible to tell whether or not Papyrus notices, would be even if he could think properly, because the moans pick up the frequency and increase in volume. There’s a hand on his head, too, and he feels some slow hip rotation, and that’s fine. That’s more than fine. His eyes open and close beneath the blindfold in what seems like random intervals, but after a time they seem to stay closed much longer than they stay open.

His brother releases into his mouth, and, on the borderline of greed, he swallows as much as he can, even stimulating the cock further as it ejaculates so he can get more. It makes his head spin and his body feel heavy. Eventually, the fountain runs out, and Papyrus withdraws. He’s so sleepy. He can’t even keep his eyes open anymore.

“You did so well, Sans,” he says, and Sans grins as his body relaxes. He’s dropping off into sleep when he hears something else.

“Now let your mind empty out, and go to sleep.”

He shudders, cums, and everything goes dark.

 

He wakes up to find himself still restrained. For a moment, he thinks, well, certainly Papyrus just forgot to take him off the chair, or something. But he opens his eyes and the room is dark save for one thing: the light.

Sans knows he’s not dreaming. It’s not that the haze in his head is any different than it’s been before, but he’s acutely aware of how real everything is. Tangible, even. The voice is still whispering things to him in a low, sweet voice, and it’s been so long since he’s even noticed it was there, but where the light usually dulls his focus and makes it impossible to look at anything else, right now he feels sharper, more aware.

The light grows closer to his face and it’s for the first time that he realizes that it isn’t a solid oval of light. It’s a magical bullet, giving off a light so strong that without trained eyes, one can’t even see the bullet’s original shape.

It’s a bone. Miniscule, but a bone nonetheless. It starts to pulsate again, and the shape becomes no clearer, but he can still tell. It’s been a bone all along.

His head feels undeniably fuzzy now from staring so intently, so he closes his eyes for a moment to process the information.

“was it me all along, then?” he asks himself, trying to piece together an idea of what could have happened. If he had sufficient control over his powers, and the desire to forget everything, well… it could have happened. He’d entertained the idea before.

The low voice stops. He feels a light touch on his collarbone, and it feels solemn and hesitant.

“No,” the other voice says, and it’s still low but it’s softer now, and Sans wonders where he’s heard that voice before. It’s a little rough, but still incredibly sexy, and he wonders if he always thought of it that way. The other one clears their throat, and then, in a voice far more familiar, they say, “No, Sans. It’s me.”

Papyrus.

Sans doesn’t move for a while, or say anything. He tries to comprehend the situation, but he’s still a little fuzzy around the edges from the light. He has so many questions.

“why?” is the first that he can conceive, and probably the most important. Papyrus chuckles and dismisses the light, walks across the room and flips on the lightswitch. They’re still in his room.

“Because you asked me to,” he says, and a wave of his hand dismisses Sans’ bindings. He can feel his magic surge back again. “You wanted to forget, and you asked me to accompany you in going around looking for help. Mettaton asked you if you really wanted to do something so sudden and boring, said you might have more fun with it if… things played out a little differently. And you… you’d been so sad for so long, and I think you were desperate to have some kind of excitement in your life, so you said that was a good idea, and you formulated a setup for this whole situation. Everyone but Undyne knew what was happening.”

His brother has an expression filled with something that looks an awful lot like regret, and Sans’ soul feels like it falls into his gut. “so… this thing between us… was all made up, then.”

Papyrus shakes his head vigorously. “N-no! That was something that I told Flowey about some time ago and I thought he’d forgotten about it. None of what happened between us was part of the plan. It just happened to flow into it very nicely.”

“hm.” Something tells him that it might be too easy an explanation, that maybe he shouldn’t be trusting his brother, but he feels safe with Papyrus, so even if the story is fabricated, it doesn’t matter much to him. “ok. i’ll probably ask you more about it later, but for now… i’m just relieved to know that it was someone that i trust to not go too far.”

“There’s a simpler way,” Papyrus says. “We made a recording, just before we started, and it included… something that would help you to remember things. Not the things you set out to forget in the first place, but… all of this. And I’d like for you to listen to it alone. It’s something that turned out poorly for me the last time that I listened to it.” He looks down. “Anyway, if there’s anything you want to say or do before you listen to that, now… would be the time.”

Sans stands up, his legs wobbly, and walks over to his brother. “bro… i know this must have been hard on you. playing a part for so long, and lying to me, even if i asked you to… but it means a lot to me. and i feel so much better than i used to. i don’t have all these nightmares wearing me down all the time, and it’s… easier to get up in the morning knowing that you’re there for me and that what happened in the past doesn’t matter anymore.”

He reaches out to hug Papyrus, and his brother lifts him up and presses his face into Sans’ bare shoulder, the tears rolling over his clavicle and falling between his ribs. “Thank you. I’m so sorry I didn’t tell you earlier.”

“nah, bro. this was a great pick-me-up. as long as everybody was into it, i don’t mind at all.” A beat, then, “does this make you, uh, my… you know. person who orders me around.”

“If you want it to,” Papyrus says.

“i do,” Sans replies, breathless as he presses his own face into his brother’s shoulder. “i really, really do. i enjoyed this a lot. especially the whole, uh, orgasm on command thing. that was pretty cool.”

“Would you like to try… other things like that?”

“like what?”

“Well, like commands that… do different things to your body or mind.”

“sure, why not? we can work on that later, though. i guess first i should probably listen to that tape or whatever… do you mind doing something first, though?”

Papyrus sounds quizzical. “Like what?”

“well… just letting me relax for a while. before i engage in something stressful, i’d like to be able to just sit back and not think for a little bit.”

“Oh!” His brother brightens up and puts him down on the bed. “I can do that. Just lie back and close your eyes, and I can do all the rest of the work.”

That sounds great to Sans, so he obeys. His eyes close and he makes himself comfortable.

“Let your mind drift, like you’re submerging yourself in a pool of water,” Papyrus says, and Sans feels pleasantly dizzy all of a sudden. “Let the water trickle up through your bones, filling your whole body with a cool numbness. You feel calm and relaxed here in the water, letting it wash away all of your thoughts and worries.”

Surrendering himself to Papyrus already felt good to begin with, but somehow the knowledge that he’s been behind all of this makes it even easier, more sublime. Relaxing is simple. Allowing his thoughts to go quiet, too, is simple. And it feels safe with his brother at the reins.

He sits, drifting without aim, and he knows peace.

**Notes for the Chapter:**

> update, 10.31.16
> 
> this fic should start updating again soon. i spent six months trying to write the next chapter and it just wasn't working out, so i decided to chop the parts that were giving me trouble so that i can actually get it finished.
> 
> keep your eyes peeled.


	12. an ending

Sans remembers everything.

Well, maybe “everything” is an exaggeration. He doesn’t remember the things he set out to forget. But the tape has brought back the memory of the plans he made, and knowing that Papyrus was telling the truth has made him feel much more secure.

And, well, Mettaton was right. It was more entertaining this way. It made him feel… alive, somehow, and in the aftermath, everything is perfect. He’s never been happier, and Papyrus is as peppy as always, and everything is just… unbelievably good.

“Unbelievably” being the operative word. Sans knows it can’t last. He may not remember anything from the old timelines, but he knows enough to be paranoid. At any time, things could be reset. At any time, something awful could happen. It’s a feeling he can’t shake, even with Papyrus’ constant reassurance that everything will be just fine.

 

It’s late August when Sans is proven right.

He wakes up to a morning like any other. He’s got sentry duty. Papyrus has the day off, but since he never takes a day off in his life, he’s sure his brother will be joining him, and maybe they’ll get up to some shenanigans on his break. He’s already looking forward to it.

Something’s making him uneasy, though. Something feels distinctly off about today. Maybe it’s just one of those days where he’s plagued by a general anxiety. He throws on his clothes and goes down the stairs. Papyrus usually tries to make breakfast for him if he’s got the morning off.

The kitchen doesn’t smell like a meal in progress, and it’s dead silent. Sans’ mind works itself into overdrive immediately, filling his head with doubt. He might just have overslept (no, he hardly sleeps, let alone this late). Maybe he got called in (no, he doesn’t take enough days off as it stands). Maybe he hasn’t come back from his morning walk yet and lost track of time. Sans clings to the idea as he bolts out the door.

It’s still a little early for anybody but Papyrus to be up, but Sans can trace his footprints in the fresh snow—even in the summer, Snowdin’s still, well, snowed in. They lead out into the forest and haven’t returned yet. Sans follows his brother’s patrol, praying that he’s just a while behind Papyrus and eventually he’ll end up being led back to his own house.

The footprints lead to the clearing where the door in the woods stands, the one the humans always came through after passing by Toriel. Papyrus isn’t here. No one is here.

The footprints stop, and several steps away, probably tossed aside by the wind, is a dust-coated red scarf.

 

_“Hello. This is, um, Papyrus, Captain of the Royal Guard, on Monday, February eighth. I am presently twenty years old, and only six days short of a third of the way through my twenty-first year. I am making this recording because my brother, Sans, sentry and hot dog vendor, whose twenty-fourth birthday is in one month and nine days, has been suffering from a strange—”_

“Sans?”

Sans pauses the recording to respond to the voice on the other side of his door. “what.”

There’s a long, awkward pause. “You wanna go to Grillby’s?”

It’s been a long two months since Papyrus died. Alphys managed to reconstruct the events well enough—the latest human would have exited the Ruins to find Papyrus on his early morning stroll. He would have offered puzzles for them, as was his custom, and at about that point he must have been attacked. Believing the best in others, it’s likely he tried to talk them out of it, she’d said, telling them that they could still be a good person—the words strike an awful chord with Sans and he’s not sure why—and then they killed him.

Sans doesn’t believe anyone who killed his brother can be a good person. Luckily for him, neither does Undyne, who had been the first to hear about the news and minutes later had tracked down the new human and sent a spear straight through them.

Toriel didn’t tell anyone that they have enough souls to break the barrier now because they want to wait until Sans recovers so he can actually appreciate the sight of the sun. Sans doesn’t know how long that’ll be. Undyne has moved in with him, both in an attempt to be closer to the entrance to the Underground to prevent this from happening again and to support Sans and make sure he’s able to take care of himself.

She sleeps on the couch because neither of them could bear to have her move into Papyrus’ room.

To her credit, she’s been trying to help as much as she can. Doing her best to get Sans out of the house, helping with chores the way Papyrus would’ve, and being less harsh on him have all helped him to cope a bit better than he would be otherwise. And it certainly helps that she wasn’t in on the plans, because his interactions with those who were have gotten pretty bad. Sans can’t even look Alphys in the eye anymore.

He listens to the recordings because that’s all he’s got left.

“sure,” he says. “why not.” As long as they get a booth and he’s facing away from Grillby he should be fine, and she knows as much. He opens his door. Undyne’s still visibly a bit of a mess, her hair down and tangled from lack of maintenance. Sans is just better at hiding his grief.

“You ready to go?” she asks, giving him a once-over. He’s pretty sure this shirt isn’t stained or anything, but even if it is, it’s not like he has the energy to change it. He nods, and she backs up, letting him close the bedroom door behind him. She runs her fingers through her hair a few times in a halfhearted attempt to make it presentable, then throws it into a ponytail anyway and starts down the stairs. Sans follows her out the door and down the way to Grillby’s, where the pair take their usual booth and Undyne flashes a few hand signals over to the bar to indicate they want what they usually have.

“How have you been holding up?” she asks, turning her attention to him, and her voice is soft. Sans hates it. Not because it sounds like pity, although it does. He hates it because she never used to talk to him that way.

“fine,” Sans lies. “better than i was.”

The two eat in silence. Undyne never knows what to say to him, and there’s nothing left for him to say. But he prefers the silence to the questions or constant pity. It’s only a little uncomfortable by comparison. Sans tries to just enjoy the meal and not start thinking too much.

“Oh,” she says, finally, as she pops the last fry into her mouth, “this weird flower outside was asking about you earlier today. Said he had something really important to tell you. About timelines or something.”

Sans’ soul leaps in his ribcage. He’s been waiting for a reset since the day it happened. “what?”

“He wouldn’t say. Just that it was super important.”

“do you mind if i go talk to him when we’re done?”

“Not at all.” Undyne shrugs. “You wanna go now?”

“yeah, kinda.”

Undyne’s gotten into the habit of covering the payment, so she puts the meal on her tab. Sure enough, when they head back, Flowey’s waiting right by the front door. “i’ll be in when i’m done,” Sans says, and Undyne enters the house as the skeleton stands out in the cold. Sans is kind of surprised to see him. They haven’t spoken since Papyrus died. In fact, he hasn’t seen Flowey at all since then. “what’s up?”

“I know you don’t remember a whole lot,” Flowey starts, “but… how much do you know about the resets?”

Sans’ face scrunches up in concern. “that they happen, mostly. the kid could cause them if something happened that they didn’t like, or if they got bored after leaving the underground. they went through a bunch of ‘em, killed everybody a couple of times. why?”

“Well,” Flowey says, “given this most recent run, I don’t think it was them that was killing everybody, but that’s neither here nor there and I don’t feel like explaining when it’s not gonna matter soon anyway. Recently I caught wind of Toriel calling them and telling them what had happened to Papyrus. Don’t know how she was able to contact them, but… anyway. They spared everybody but Asgore, right? That was your job, to keep track.”

“yeah.” Sans sighs. “not that it matters, but.”

“No, no, it does matter.” The golden flower flails his leaves a little. “I can’t reset because of the kid’s interference. But… Toriel may not have understood what they were getting at when they said they’d fix the problem, but I did. The next time they load, they’re going to be back here. And they’re going to have things set up for a pacifist timeline.”

“what’s that mean.” Sans wishes Flowey would just get to the point, but he doesn’t want to piss off the flower for obvious reasons.

“It means Papyrus is going to be alive again.”

Sans stares at Flowey for a long minute. “you better not be fucking with me.”

“I’m not! Honestly, I considered not even telling you and just letting you see it for yourself, but I… figured Paps would want you to know, and I… care about him or some stupid shit. So I’m doing it out of respect for him, not because I like you. But I’m gonna remind you, again, because I figured he’d want you to know, that you’ll be going back to before the kid left. Before Asgore died. And everything that entails. I hope I don’t have to spell it out for you.”

Sans shrugs. “i don’t really care what it entails as long as he’s alive again.”

“Alright, well, cool,” Flowey says. “I picked up this information this morning, so it could be… any time. But it’ll be soon, I can feel it.”

“thanks for letting me know,” Sans replies. “it… means a lot to me.”

“I know.”

With that, the flower disappears, and for the first time in a long time, Sans feels hope.

**Notes for the Chapter:**

> almost a full year later and i finally manage to put out an update again. i'm gonna be alternating chapters of this with another fic i'm working on so it should get finished... sometime soon. i hope.
> 
> please note there's still two chapters left; this isn't where things finish in spite of the chapter's title.


	13. good night.

**Notes for the Chapter:**

> I ended up deciding to merge the two chapters into one, and make it significantly shorter than I was expecting, because otherwise I'm going to be sitting on this forever.
> 
> You'll notice I've orphaned this after I posted it; I'm not really into Undertale anymore but I wanted to finish this and leave it for the fandom.
> 
> Hope you enjoyed the ride.

When Sans wakes up, things are undeniably different.

For starters, he’s not even in his room where he’s pretty sure he fell asleep. He’s in New Home, where he’s supposed to deliver his speech about whether the kid’s killed anyone or not.

They’re doubling back frantically now, power-walking silently through the room and giving him a halfhearted wave as they pass. Sans’ soul lifts in his chest as he pulls out his phone and dials his brother’s number.

“Yes, Sans? I hope this isn’t part of a joke, Undyne’s just come to me with a matter of utmost importance!”

Sans’ eye sockets start to fill with tears. “nah, bro. i just wanted to hear your voice.”

“Well, alright then! I hope you’re doing well and I believe in you!”

“i’m doing great, papyrus,” Sans says, wiping his eyes with the sleeve of his hoodie. “i’m the luckiest skeleton in the world, to have such a cool bro as you.”

“You are!” Papyrus affirms. “I’ve got to get back to work helping Undyne and advising the human, but you sound upset. We can talk later if you need to!”

“alright. talk to you later,” he says, and hangs up.

Papyrus is alive.

Papyrus doesn’t remember anything that’s happened between the two of them.

At least he’s alive, Sans tells himself, and tries not to make things weird.

 

Throughout the human’s trek through the underground to befriend Alphys, Sans thinks.

Papyrus allegedly had these feelings before Flowey had brought them up, but for how long?

 

That night, when he’s still lying in bed wide awake while the human investigates the True Lab, he sees a hand with a hole through the center phase through the wall and place a DVD on his dresser. It’s unfamiliar, but the hand isn’t. Soft static fills his skull.

[* Give this to Papyrus when you have the opportunity.]

“wait,” Sans says. “i thought you couldn’t leave the room—“

The hand vanishes back into the wall.

 

Frisk sets the underground free.

It’s during Sans’ first breath of fresh air that he instinctively reaches for Papyrus’ hand, then flinches away when he realizes what he’s doing. Papyrus seems to notice, but says nothing.

They find a city. People aren’t the most welcoming of them, but Frisk works as an excellent intermediary. Soon enough, there’s temporary housing in a local hotel for many of the monsters that chose to leave Mt. Ebott, Papyrus and Sans included. Sans searches the room for a DVD player while Papyrus showers, but when he inserts it, the face that meets him is Papyrus’ own.

“If this is Sans, when I’m done explaining, please pause this video and ask me to come into the room. I assume I don’t remember anything about us. About what happened. Otherwise, Gaster wouldn’t have delivered this to you.”

Sans can’t breathe.

“You can watch if you’d like, but it won’t do much for you. I know what will bring back my memories, and I intend to do so in this video. So! Please pause the video and wait for me to come back.”

As he’s scrambling for the pause button, Sans hears the shower turn off. “Sans?” Papyrus calls from the bathroom. “I thought I heard my voice out there. What’s going on?”

“got a video for you to watch,” Sans replies. “uh, it’s really interesting, it’s something you recorded for yourself, actually.”

“What? I don’t remember doing any such thing.”

“yeah,” Sans replies, “i know.”

Papyrus exits the bathroom quite suddenly. He’s only just barely dry, and he’s not wearing anything. Sans only just keeps himself from staring. “That’s me!” he says, looking at the screen. “Is this one of your pranks?”

“nope.” Then, without letting Papyrus get any more suspicious, he presses play.

The light comes onto the screen, and immediately Sans is transfixed. It’s still able to draw him in somehow, and he can feel himself relax. Papyrus is saying something on the television, but he doesn’t know what it is. The Papyrus in the room with him sits down on his bed, staring at the screen just as he is.

Sans can’t keep his eyes open very long. They slide shut, and he falls back onto the bed, taking the voice into his entire being.

He’s missed this, he thinks as he drifts out.

 

Sans wakes to Papyrus curled against him in bed. He turns, looking at his younger brother, and Papyrus stirs.

“Hello, Sans,” he says, and kisses Sans on his forehead.

This is a world Sans thinks he can face.


End file.
